(b) Draw a labelled diagram to show how an electromagnet is made. Direction of force on a current carrying conductor is determined by Flemings left hand rule. Explain why alternating current is preferred over direct current for transmission over long distances. Thus, the value of the magnetic field comes out to be 13.33 $\times$ 10-7 tesla. A variety of questions can be framed from magnetic fields due to straight wire and so you need to practise as many problems as possible. WebAn electromagnetic coil is an electrical conductor such as a wire in the shape of a coil (spiral or helix). (i) vertically in North South plane and an observer looking it from east sees the current to flow in anticlockwise direction, Compass needle is used to draw magnetic field lines. (a) current flowing in the conductor This is due to the reason that the current in all the circular turns of the coil is in the same direction. Answer: Obviously, the electric current will flow through the body of the person who touches the appliance. Answer: (Board Term I, 2015) The potential difference between these wires is 220 V. Question 19. a) Magnetic field due to a current through a straight conductor. The direction of magnetic field depends on the direction of current in conductor. Magnetic field pattern due to straight current carrying conductor are concentric circles whose center lie on the wire. Connect the aluminium rod in series with a battery, a key and a rheostat. (1/3, 2020) Question 3: A straight current-carrying conductor produces a magnetic field of 5T at a distance of 2 m. Find the magnitude of the electric current flowing through it. Strength of magnetic field produced by a straight current-carrying wire at a given point is Question 47. (a) Live wire is at 220V and neutral wire is at zero volt since the electric current flows from higher potential to lower potential, we can get an electric shock by touching live wire but that is not the case with neutral wire. (b) strength of magnetic field Question 25. In that context, it is also called the Laplace force . (b) (i) If the current is increased, the magnetic field strength also increases. By keeping the magnet in a fixed position and moving the coil towards and away from the magnet, we can induce current in the coil. (d) both, direction and magnitude of the induced current. (2020) If a fuse of higher rating is used then it may not melt and cut off the supply during overloading. You can use your right hand, as depicted, to determine the direction of the magnetic field. (i) Earth wire, (ii) Main fuse At which distance is the magnetic field 2 $\times$, Thus, the distance at which the magnetic field is 2 $\times$, Example 3: Find the electric field at 6m from an infinitely long wire with a linear charge density of 8 x. cm. WebMagnetic field lines of a Neodymium Magnet as illustrated below with the iron filings. Now answer the following. Hence deflection of compass decreases when it is displaced away from the conductor. (d) List two ways of increasing the strength of an electromagnet if the material of the electromagnet is fixed. Answer: (1/3, Board Term I, 2013) That is Curl the palm of your right hand around the circular wire with the fingers pointing in the direction of the current. Answer: Answer: This is due to the reason that the metallic casing will be at the same potential as the applied one. Suppose we assume a point P at a distance r from a long straight wire carrying current I. From this pattern, the following important conclusion have been drawn. WebThe latest Lifestyle | Daily Life news, tips, opinion and advice from The Sydney Morning Herald covering life and relationships, beauty, fashion, health & wellbeing Let us now discuss the force due to the magnetic field in a straight current-carrying rod. Answer: The properties of the magnetic field lines are listed below: In order to find the magnetic field due to a coil, it is held in a vertical plane and is made to pass through a smooth cardboard in such a way that the centre (O) of the coil lies at the cardboard. (Delhi 2019) Short circuiting: The condition when the live wire comes in direct contact with the neutral wire, due to which a high current flows in the circuit. Question 37. (b) direction of current is reversed? Name the device which is used to draw magnetic field lines. Also draw field lines inside the solenoid. Hence there will be no deflection in the galvanometer. Direct current (D.C.) : An electric current whose magnitude is either constant or variable but the direction of flow in a conductor remains the same is called direct current. To avoid such serious accidents, the metal casing of the electric appliance is earthed. Answer: Magnetic Field Due to Current Carrying Conductor If a magnetic compass is placed near a conductor carrying current (wire), the needle is deflected. (1/3, Board Term I, 2013) (b) In household circuit, parallel combination of resistances is used. Name the rule which determines the direction of this force. CBSE Important Questions for Class 10 Science, NCERT Solutions for Class 10 ScienceChapter 1, NCERT Solutions for Class 10 ScienceChapter 2, Periodic Classification of Elements Class 10, NCERT Solutions for Class 10 ScienceChapter 7, NCERT Solutions for Class 10 ScienceChapter 8, NCERT Solutions for Class 10 ScienceChapter 9, NCERT Solutions for Class 10 ScienceChapter 10, NCERT Solutions for Class 10 ScienceChapter 11, NCERT Solutions for Class 10 ScienceChapter 12, NCERT Solutions for Class 10 ScienceChapter 13, NCERT Solutions for Class 10 ScienceChapter 14, NCERT Solutions for Class 10 ScienceChapter 15, NCERT Solutions for Class 10 ScienceChapter 16, CBSE Previous Year Question Papers Class 12, CBSE Previous Year Question Papers Class 10. Question 27. If you get stuck do let us know in the comments section below and we will get back to you at the earliest. The field lines become straight and perpendicular to the plane of the coil at the centre of the circular wire. If the current decreases, the magnetic field decreases, inducing a voltage in the conductor in the opposite direction, negative at the end through which current enters and positive at the end through which it leaves. Give reason for your answer. \({B_x} = \frac{{{\mu _0}I{R_x}^2}}{{2{{\left( {{x^2} + {R^2}} \right)}^{3/2}}}}\) Necessary parameters are: (b) If field lines of a magnetic field are crossed at a point, it indicates that there are two direction of magnetic field at a point which is not possible. Answer: (a) State Flemings Left-hand rule. (c) The soft iron core placed in an electromagnet increases the strength of the magnetic field produced. Question 24. WebAn electric current flowing in a wire creates a magnetic field around the wire, due to Ampere's law (see drawing below). Answer: Question 22. (b) Draw circuit diagram of a solenoid to prepare an electromagnet. Electric field on the other hand is denoted as $E=\dfrac{\lambda}{2 \pi \in{ }_{o}{r}}$, which is again inversely proportional to the distance of the point from the wire. For the magnetic field at the centre of the loop, put \((x = 0)\) in the above expression. A long straight wire carrying current will produce a magnetic field. Example 1: A wire of 60 cm in length carries a current I= 4 A. Stay tuned to Embibe for more updates on the Magnetic Field on the Axis of a Circular Current Loop. For this, put the north pole of the magnet vertically below and south pole vertically above the aluminium rod. (c) Flemings right hand rule: Stretch the right hand such that the first finger, the central finger and the thumb are mutually perpendicular to each other. (ii) When is the magnitude of this force maximum? According to the Biot-Savart law, we can get that the magnetic field \({\text{d}}\overrightarrow B \) at a point \(P\), due to an element \(({\text{d}}\overrightarrow l )\) which is carrying a steady current \((I)\) at a distance \((\overrightarrow r )\) from the current element is given as (a) What is meant by a magnetic field? To concentrate the magnetic field, in an electromagnet the wire is wound into a coil with many turns of wire lying side by side. Example 4: A straight current-carrying conductor is carrying a current of 10A and another conductor parallel to it carries a current of 15A on the opposite side as shown in the figure below. Compare the two cases. Answer: Refer to answer 15(i). (2020) If the current through the wire increases, the magnitude of the magnetic field produced at a given point also increases. Question 9. Plugging in the values into the equation, (i) List the factors on which the magnitude of force experienced by conductor depends. Question 28. Answer: (ii) Increasing the number of turns in the coil. WebMagnetic Force on a Current-Carrying Conductor. WebHelical Motion in a Magnetic Field A proton enters a uniform magnetic field of 1.0 10 4 T 1.0 10 4 T with a speed of 5 10 5 m/s. Flemings Right-hand rule gives Question 29. Magnetic fields are produced when current passes through a wire or a loop. Electromagnets are used in electric motors and generators, electric bells and buzzers, loudspeakers and headphones etc. Give reason for your answer. (a) Refer to answer 22(iii). State how the magnetic field produced by a straight current carrying conductor at a point depends on (a) current through the conductor (b) distance of point from conductor. The magnetic field lines due to a current-carrying circular wire form a closed loop which is shown in Fig.(c). Inversely, it can also be stated that if the thumb represents the direction of current, then the fingers denote the direction of the magnetic field. (Board Term I, 2015) These iron filings arrange themselves in a pattern similar to one shown in the figure. Galvanometer is an instrument that can detect the presence of electric current in a circuit. (i) west to east (a) direction of magnetic field is reversed? Repeat the above procedure and draw as many lines as you can. Question 33. Question 10. (i) increasing the current through the conductor (2020) Near the centre of the coil, the field lines are nearly straight and parallel. (c) (i) Armature is a conductive part of motor which generates torque in the motor. What is a solenoid? Question 30. WebMagnetic Field Of A Straight Line Current. (b) Name the phenomena involved in the above cases. (i) The frequency of household supply of A.C. in India is 50 Hz. The electric field for a long straight current-carrying wire is denoted as: $E=\dfrac{\lambda}{2 \pi \in{ }_{o}{r}}$. Answer: Give reason to justify your answer in each Question 42. Diagram shows the lengthwise section of a current carrying solenoid. We hope this detailed article on Magnetic Field on the Axis of a Circular Current Loop helps you in your preparation. Using Flemings left hand rule, the direction of magnetic field is out of the plane of paper. Draw the magnetic field lines through and around a single loop of wire carrying electric current. Write one application of right hand thumb rule. This field can be calculated by considering an infinitely long straight wire and then using a cylindrical gaussian surface. indicates current entering into the page, indicates current emerging out of the page. WebThe magnetic force component of the Lorentz force manifests itself as the force that acts on a current-carrying wire in a magnetic field. Why is it called a safety device? (b) Magnetic field are closed curves. Yes, these will be an induced current in both the cases as there is a change in the number of magnetic field line associated with the coil or we can say that there is a motion of a magnet with respect to the coil. Mention and explain the function of an earth wire. (Board Term I, 2017) We can use separate on/off switches with each appliance. This is because, a potential difference and thus a current is induced in coil 2 as there is change in the current and the magnetic field associated with it in coil 1. So, it is safe and convenient to connect household circuit in parallel combination of resistors WebThe Concept of Magnetic Field Due to a Current Through a Straight Conductor. (2/3, 2020) Question 40. WebSolenoids have many practical implications and they are mainly used to create magnetic fields or as electromagnets. (i) There is either a convergence or a divergence of magnetic field lines near the ends of a current carrying straight solenoid because it behaves similar to that of a bar magnet and has a magnetic field line pattern similar to that of a bar magnet. (a) Strength of magnetic field produced by a current carrying solenoid depends upon the following factors: (b) A strong magnetic field produced inside a solenoid can be used to magnetise a piece of magnetic material, like soft iron, when placed inside the coil. The direction of the force produced by a long wire is given by the right hand thumb rule. Thus, the total magnetic field B at point P can be written as, $\begin{align} &B=B_{1}-B_{2} \\ &B=10^{-6}-0.75 \times 10^{-6} \\ &B=0.25 \times 10^{-6} \mathrm{~T} \end{align}$. (Board Term I, 2014) In case, two magnetic field lines intersect each other at the point P as shown in figure, magnetic field at P will have two directions, shown by two arrows, one drawn to each magnetic field line at P, which is not possible. By using, Biot Savarts law we are now finding the magnetic field at a point p, which is at a distance r from the wire . Draw magnetic field lines around a bar magnet. This force deflects the charged particle from its path. WebMagnetic fields are produced when current passes through a wire or a loop. Q.5: What is a circular loop?Ans: A circular loop is made up of a large number of very small straight wires. List any two uses. Question 15. Magnetic field : It is defined as the space surrounding the magnet in which magnetic force can be experienced. It must be noted that this rule is applicable for a conductor moving in a magnetic field to find the direction of force acting on it. (Board Term I, 2014) When the direction of current flowing through the rod is reversed, the displacement of rod will be towards right. Solenoid is used to form strong but temporary magnet called electromagnets. (a) Fuse and the connection of earthing wire are the two safety measure commonly used in electric circuit and appliances. Question 26. An induction motor's rotor can be either (c) Fuse is an important safety device. (b) Principle : Current carrying conductor when placed at right angle to a magnetic field, experiences a force due to which we get motion. Q.1: How do you find the direction of the magnetic field on the axis of the circular loop?Ans: The direction of the magnetic field is given by the right-hand thumb rule. Answer: (ii) Force experienced by a current carrying conductor placed in a magnetic field is largest when the direction of current is perpendicular to the direction of magnetic field. Solved Examples on Magnetic Field Due to Straight Wire, Thus, the value of the magnetic field comes out to be 13.33 $\times$ 10, Example 2: A wire of 60 cm in length carries a current I= 3 A. (a) vary continuously (b) does not change 5. We can use the Biot-Savart law to find the magnetic field due to a current. The magnetic field is created due to current and its strength depends on the magnitude of the current. The forces exerted on the current-carrying wires create a torque on the coil. (b) Magnetic field produced by solenoid is more stronger than magnetic field of a bar magnet. (ii) The two stationary brushes in a simple electric motor draw current from the battery and supply it to the armature of motor. The direction of the force is given by Flemings left hand rule. Inside the solenoid field lines are in the form of parallel straight lines. Answer: (i) Alternating current has a frequency of 50 Hz. Question 31. This shows that a conductor carrying current has a magnetic field around it. When the magnetic field changes in coil 1, the magnetic field lines around coil 2 also changes. Imaginary continuous closed curves used to represent the magnetic field in a region is known as magnetic field lines. The magnetic field (capital letter "B") is represented by the red arrows. (a) If a coil of insulated wire is connected to a galvanometer and a bar magnet with south pole is moved towards one face of the coil then, given situation is shown in the figure. (Board Term I, 2017) Oersteds experiment: According to this experiment A current carrying wire creates a magnetic field around it. We derive this force on the wire using Biot's Savart's Law. Electromagnetic coils are used in electrical engineering, in applications where electric currents interact with magnetic fields, in devices such as electric motors, generators, inductors, electromagnets, transformers, and sensor coils.Either an electric Thus, the magnetic field created by the current-carrying wire is denoted as the ratio of the product of magnetic permeability and current to its distance from the wire. Answer: To find the magnetic field formula due to an infinitesimally small current-carrying wire at some point, we use the Biot-Savart law to calculate the magnetic field of a highly symmetric configuration carrying a steady current Amperes Circuital Law. \(B = B_1 B_2\) Problems on Force between Two Parallel Current Carrying Conductors. (Board Term I, 2017, 2016) Question 34. (c) Flemings Right-hand rule gives the direction of induced current. \({B_2} = \frac{{{\mu _0}I{R^2}}}{{2{{\left( {{x^2} + {R^2}} \right)}^{3/2}}}}\) (a) State three factors on which the strength of magnetic field produced by a current carrying solenoid depends. Previous Year Questions & Important Questions of Magnetic Effects of Electric Current Class 10 Science Chapter 13 will help the students to score good marks in the board examination. Magnetic field lines start at the north pole and end at the south pole. The gauss law can then be used to find the electric field of this straight wire. WebElectrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current.A low resistivity indicates a material that readily allows electric current. (Board Term I, 2017) (a) current through the conductor (2020) Flemings left hand rule is as follows: (iii) into the paper. (Board Term I, 2016) One isBiot-Savart law, and the other isAmperes law. The direction of a magnetic field produced due to a current-carrying conductor relies upon the same direction in which the current is flowing. These are known as magnetic field lines. WebThis illustration shows the magnetic field around a current-carrying wire. Answer: Can you determine the north and the south poles of a current-carrying solenoid with the help of a bar Leading AI Powered Learning Solution Provider, Fixing Students Behaviour With Data Analytics, Leveraging Intelligence To Deliver Results, Exciting AI Platform, Personalizing Education, Disruptor Award For Maximum Business Impact, Take Free Mock Tests related to Magentic Field, Magnetic Field on the Axis of a Circular Current Loop. List two properties of magnetic lines of force. Resistivity is commonly represented by the Greek letter ().The SI unit of electrical resistivity is the What are magnetic field lines? \( \Rightarrow {B_2} = 3.9 \times {10^{ 5}}\;{\text{T}}.\). Question 12. (iii) placed near its one face? What is the magnetic field at 50 cm from the wire? Question 32. Thus, the magnetic field lines are closed curves. Embiums Your Kryptonite weapon against super exams! Answer: This means, A.C. completes 50 cycles in one second. Answer: Substituting these in the above formula, we get, The problem has two wires. Draw a diagram to show field lines of the magnetic field through and around a current carrying solenoid. (iii) Placed near its one face : No deflection of the needle of galvanometer is observed. Question 7. These electromagnets are used in wide variety of instruments and used to lift heavy iron, objects. The index finger here will denote the direction of the velocity of the conductor, the magnetic field denotes the direction of the magnetic field, and the thumb depicts the force acting on the conductor. (ii) The current carrying solenoid behaves similar to that of a bar magnet and when freely suspended aligns itself in the north-south direction. Answer: The magnitude of the magnetic field at the centre of the coil is directly proportional to the current flowing through it and total number of turns and inversely proportional to the radius of the coil. \(B = \frac{{{\mu _0}I{R^2}}}{{2{{\left( {{x^2} + {R^2}} \right)}^{3/2}}}}\), and (c) Explain the function of the following parts of an electric motor. A variety of questions can be framed from magnetic fields due to straight wire and so you need to practise as many problems as possible. Answer: (a) What is an electromagnet? WebIt is a vector quantity that defines the area of influence of the magnet. Find the magnitude of the magnetic field produced by the system at a distance of 2 m. Solution: The problem has two wires. Thus, the magnetic field due to a long straight current carrying wire is inversely proportional to the distance of a point P from the wire. We can use the Biot-Savart law to find the magnetic field due to a current. What is meant by magnetic field? Write one application of Flemings right hand rule. Let the magnetic field by wire carrying 10A current be, by second wire carrying current 15 A and at distance 4m from P can be given as, So, the magnetic field by both wires at point P is 0.25$\times$, Magnetic field due to straight wire comes under the chapter magnetic effects of current and magnetism. (b) Write the principle of working of an electric motor. When an electric current, flows through a circular coil of wire, then a magnetic field is produced. A charge moving in a straight line, as through a straight wire, generates a magnetic field that spirals around the wire. Now we can find the magnetic field by individual wires and then add them to get the total magnetic field. The chapter on magnetic effects of current and magnetism has a weightage of about 6.6% in. Question 23. WebGrid energy storage (also called large-scale energy storage) is a collection of methods used for energy storage on a large scale within an electrical power grid.Electrical energy is stored during times when electricity is plentiful and inexpensive (especially from intermittent power sources such as renewable electricity from wind power, tidal power and solar Write any one method to induce current in a coil. Q.4: How is the variation of the magnetic field on the axis of a circular loop?Ans: The magnetic field is maximum at the centre, and it goes on decreasing as we move away from the centre of the circular loop on the axis of the loop. \({B_1} = \frac{{{\mu _0}I}}{{2R}}\) (a) As the amount of magnetic field strength is directly proportional to the amount of current, so the deflection of compass needle increases. Give reasons for the following: Question 36. Moreover, a strong current is required to produce a strong magnetic field. Question 6. Answer: Answer: WebFigure 12.11 Determining the magnetic field at point P along the axis of a current-carrying loop of wire. Properties of magnetic filed lines : Ans: The net magnetic field is the difference between the two fields generated by the coils because the currents are flowing in opposite directions. Answer: Why it is necessary to earth metallic appliances? Describe in brief an activity to study the magnetic field lines due to a current carrying circular oil. NCERT Solutions for Class 6, 7, 8, 9, 10, 11 and 12. Describe an activity with labelled diagram to show that a force acts on current carrying conductor placed in a magnetic field and its direction of current through conductor. Answer: Right Hand Thumb Rule: The right hand thumb rule states that when we curl our fingers in the direction of the magnetic field, the direction of the thumb gives the direction of the current. The magnetic field for a long straight infinite current carrying wire is inversely proportional to its distance from the wire. As such, the resultant magnetic field due to the coil is equal to the sum of the field due to all these turns. (b) Distinguish between short circuiting and overloading. Using this formalism and the principle of superposition, we will define a magnetic field and calculate the total magnetic field due to the circular current loop. Answer: Resistivity is commonly represented by the Greek letter ().The SI unit of electrical resistivity is the Check here to use the Biot-Savart law to calculate a small current elements magnetic field produced at some point in space. (b) If both the coils are moved in the same direction with the same speed, then there is no net change in magnetic flux. Answer: That is, the field is uniform inside the solenoid. Assuming a long straight current carrying a wire of magnitude I, the magnetic field (B) created by the conductor is formed around it. Answer: (a) directly proportional to the current passing through it. The frequency of A.C. in India is 50 Hz and it changes direction twice in each cycle. Find the direction of magnetic field due to a current carrying circular coil held: (b) magnitude of the magnetic field. Justify your answer. The magnetic field can also be seen with a piece of Magnetic View Film Green 4x6". Enjoy your trip from in-flight, such as Food, Drink, Limited goods and Tickets. The change in magnetic field lines in a coil is the cause of induced electric current it. We need to calculate the magnetic field for the entire conductor. Answer: Decide which end of the solenoid A or B, will behave as north pole. \( \Rightarrow B = \frac{{{\mu _0}I{R_1}^2}}{{2{{\left( {{x_1}^2 + {R_1}^2} \right)}^{3/2}}}} \frac{{{\mu _0}I{R_2}^2}}{{2{{\left( {{x_1}^2 + {R_2}^2} \right)}^{3/2}}}}\) Question 46. We can write B1 as, $\begin{align} &B_{1}=\dfrac{\mu_{o}{I}_1}{2 \pi r_{1}} \\ &B_{1}=\dfrac{2 \mu_{o} \times 10}{4 \pi \times 2} \\ &B_{1}=10^{-7} \times 10 \\ &B_{1}=10^{-6} \mathrm{~T} \end{align}$, Similarly, the magnetic force B2 by second wire carrying current 15 A and at distance 4m from P can be given as, $\begin{align} &B_{2}=\dfrac{\mu_{0} I_{2}}{2 \pi r_{2}} \\ &B_{2}=\dfrac{2 \mu_{0} \times 15}{4 \pi \times 4} \\ &B_{2}=10^{-7} \times \dfrac{15}{2} \\ &B_{2}=0.75 \times 10^{-6} \mathrm{~T} \end{align}$, Now, both the wires have opposite directions, so the total magnetic field will be given by the difference of their individual magnetic fields. \(B = \frac{{{\mu _0}I}}{{2R}}\), Q 1. (Board Term I, 2016) (Board Term I, 2016) c) Magnetic field due to a current through a circular loop. (Board Term I, 2017) Example 2: A wire of 60 cm in length carries a current I= 3 A. Q 2. (Board Term I, 2017) A charged particle moving in a magnetic field may experience a force in the direction perpendicular to direction of magnetic field and direction of motion of particle. At what angle must the magnetic field be from the velocity so that the pitch of the resulting helical motion is equal to the radius of the helix? I is the current intensity flowing in the long wire. (a) Magnitude of electric current is increased. Answer: (a) When the amount of current in the coil P is changed, an induced current will induce in the coil Q due to change in magnetic field lines i.e., magnetic flux. Answer: WebNews on Japan, Business News, Opinion, Sports, Entertainment and More The direction of this current can be found out from Maxwell's right thumb rule. (i) Increasing the current passing through the coil. The right-hand thumb rule can be used for a circular conducting wire as well as it comprises small straight segments. \( \Rightarrow {B_2} = {B_1}\left[ {\frac{{{R^3}}}{{{{\left( {{x^2} + {R^2}} \right)}^{3/2}}}}} \right]\) (c) direction of the induced current. Magnetic Field due to Current in Straight Wire. The force F on a wire of length L carrying a current i in a magnetic field B is iLB times the sine of the angle between B and i, which would be 90 if the field were uniformly vertical. The right hand thumb rule states that when we curl our fingers in the direction of the magnetic field, the direction of the thumb gives the direction of the current. \(\Rightarrow {B_2} = \left( {0.5 \times {{10}^{ 4}}} \right)\left[ {\frac{{{{\left( {12} \right)}^3}}}{{{{\left( {{5^2} + {{12}^2}} \right)}^{3/2}}}}} \right]\) 4. Magnetic field due to current in a solenoid If the insulation of any of these appliances melts and makes contact with the metallic casing, the person touching it is likely to receive a severe electric shock. B is the magnetic field measure in tesla. When current is passed through a straight current-carrying conductor, a magnetic field is produced around it. (i) There is either a convergence or a divergence of magnetic field lines near the ends of a current carrying straight solenoid. Answer: Magnetic field is maximum at its centre. (ii) Magnetic field lines around a bar magnet. Answer: Using the given quantities in the problem, the net magnetic field at point \(P\) can be calculated by the equation given below:Solving for the magnitude of net magnetic field using the equation and the quantities in the problem yields: Answer: Give reason for the following WebElectrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current.A low resistivity indicates a material that readily allows electric current. $\begin{align}&r=\dfrac{\mu I}{2 \pi B}=\dfrac{4 \pi \times 10^{-7} \times 3}{2 \pi \times 2 \times 10^{-3}} \\ &r=0.6 \times 10^{-4} \mathrm{~m}=0.06 \mathrm{~mm} \end{align}$. (Board Term I, 2015) Hence, the value of electric field is $0.047 \times 10^{9}\,N/C$. The field lines are in the same direction in the space enclosed by the coil. Question 21. (b) Overloading : The condition in which a high current flows through the circuit and at the same time too many appliances are switched on then the total current drawn through the circuit may exceed its rated value. Therefore, it changes direction 2 50 = 100 times in one second. The pattern of magnetic field lines so obtained is shown in figure (b). Since the earth does not offer any resistance, the current flows to the earth through the earth wire instead of flowing through the body of the person. (b) How will the magnetic field be affected on: (ii) Key K is opened Procedure for CBSE Compartment Exams 2022, Find out to know how your mom can be instrumental in your score improvement, (First In India): , , , , Remote Teaching Strategies on Optimizing Learners Experience, MP Board Class 10 Result Declared @mpresults.nic.in, Area of Right Angled Triangle: Definition, Formula, Examples, Composite Numbers: Definition, List 1 to 100, Examples, Types & More. (2020) (b) List three characteristic features of the electric current used in our homes. (ii) moved quickly away from it, List three characteristics of these lines. There are two methods of calculating magnetic fields in magnetics at some point. (i) When a current carrying wire is placed in a magnetic field, it experiences a magnetic force that depends on State the direction of magnetic field in the following case. (iii) Often, there are two separate circuits used in our homes, one of 15 A current rating for appliances with higher power rating and the other circuit of 5 A rating for appliances such as fans, bulbs, etc. When a current-carrying wire is exposed to the magnetic field it also experiences forces because the charges are moving inside the conductor. This induces a current in coil 2. (Board Term I, 2016) So, fuse acts like a watchman in an electric circuit. Also in case if any one resistor fails then the circuit will not break. Answer: Question 44. Following are the distinguishing features between the two fields. (ii) north to south You can buy Peach goods from overseas! Answer: The magnitude of the magnetic field due to a circular coil of radius \((R)\) carrying a current \((I)\) at an axial distance \((x)\) from the centre is given as Stretch the thumb, middle, and index finger of your right hand perpendicular to one another. Question 45. Then your finger will wrap around the conductor in the direction of the field lines of the magnetic field. Coil 1 has comparatively large number of turns. When the device is placed within a magnetic field, the magnetic flux lines exert a force on the semiconductor material Name the underlying phenomenon. Place a strong horseshoe magnet in such a way that the rod lies between the two poles with the magnetic field directed upwards. Answer: (ii) reversing the direction of flow of current in the conductor? (a) It states that you are holding a current carrying straight conductor in your right hand such that the thumb points towards the direction of current. The pattern of magnetic field lines inside the solenoid indicates that the magnetic field is the same at all points inside the solenoid. It is used to find the direction of magnetic field around a current carrying conductor. Question 2. Justify your answer in each case. (iv) (a) Direction of force will be reversed when direction of magnetic field is reversed, i.e., now force on conductor will act from left to right. Then, the limits of the integral will be from 0 to infinity. Answer: Thus, the magnetic field created by the current-carrying wire is denoted as the ratio of the product of. These lines represent the magnetic field around the magnet. State how the magnetic field produced by a straight current carrying conductor at a point depends on Answer: (Board Term I, 2017) (b) If field lines of a magnetic field are crossed at a point, what does it indicate? (iv) If initially this force was acting from right to left, how will the direction of force change if: iii) The magnetic field lines do not intersect each other. A current carrying conductor is placed in a magnetic field. (i) Key K is closed Thus, the distance at which the magnetic field is 2 $\times$ 10-3 T is 0.06 mm. (ii) Mention the frequency of D.C that is given by a cell. Define the term induced electric current. (c) Using fuse in a household electric circuit is important. Magnetic field lines can visualise the magnetic field of a straight current-carrying conductor. Question 38. Define alternating current and direct current. \(\frac{{{B_2}}}{{{B_1}}} = \frac{{{R^3}}}{{{{\left( {{x^2} + {R^2}} \right)}^{3/2}}}}\) CBSE Previous Year Question Paper for Class 10, CBSE Previous Year Question Paper for Class 12. Thus, Two coils of insulated copper wire are wound over a non-conducting cylinder as shown. \( \Rightarrow B = \frac{{\left( {4{{\pi }} \times {{10}^{ 7}}} \right)\left( {0.010} \right){{\left( {0.5} \right)}^2}}}{{2{{\left( {{{0.25}^2} + {{0.5}^2}} \right)}^{3/2}}}} \frac{{\left( {4{{\pi }} \times {{10}^{ 7}}} \right)\left( {0.010} \right){{\left( 1 \right)}^2}}}{{2{{\left( {{{0.75}^2} + {1^2}} \right)}^{3/2}}}}\) (ii) No, alpha particle will not experience any force if it moves in the magnetic field parallel to field lines because charge particle experiences force only when it moves at an angle other than 0 with magnetic field. Thus the ends of the straight solenoid behaves like poles of the magnet, where the converging end is the south pole and the diverging end is the north pole. Question 17. Question 35. Q.2: What is the magnetic field due to a current-carrying loop?Ans: The magnetic field on the axis of a current-carrying loop is given by:\({B_x} = \frac{{{\mu _0}I{R_x}^2}}{{2{{\left( {{x^2} + {R^2}} \right)}^{3/2}}}}\widehat i\)where \(x\) is the distance of that point on the axis from the centre of the loop, \(R\) is the radius of the loop, and \(I\) is the current flowing in the loop. What is the weightage of the magnetic field due to a straight wire in JEE? An electric generator is mechanically identical to an electric motor, but WebMagnetic field due to current through a circular loop. In order to find the direction of magnetic field lines, we plot the magnetic field with the help of a compass needle. Direct current always flow in one direction whereas the alternating current reverses its direction periodically. State the use of magnetic field produced inside a solenoid. In this article, let us learn about magnetic field intensity due to a straight current-carrying conductor of finite length. Give reason for the following : (Board Term I, 2013) The magnetic field also further depends on the distance of the wire. The. It is an extremely important topic and has a high chance of being asked in the exam. As such the magnetic field at the centre of the coil can be taken to be uniform. (iii) The rule used in finding the direction of motion of the conductor placed in a magnetic field is Flemings left hand rule. (Board Term I, 2017) (b) What precaution should be taken to avoid the overloading of domestic electric circuits? (Board Term I, 2014) This is because, when the current stops flowing in coil 1, the magnetic field associated with it changes in the opposite direction as in the first case, thus inducing a current in the opposite direction. One can easily demonstrate the presence of field lines around a bar magnet using compass needles. Now move the compass such that its south pole occupies the position previously occupied by its north pole. and at least 2 questions are asked every year from this topic. Flemings left hand rule is used to find the direction of force on a current carrying conductor placed in a magnetic field acting perpendicular to the direction of current. Write the frequency of alternating current (AC) in India. What is the function of a galvanometer in a circuit? Two circular coils P and Q are kept close to each other, of which coil P carries a current. WebAn induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. If two loops of wire carry the same current of \(10\,\rm{mA}\), but the flow of current is in opposite directions. (c) A fuse is safety device use to limit the current in an electric circuit. Answer: (a) if current in the coil P is changed? (b) distance of point from conductor. r is the distance of the magnetic field from the wire. Find the magnetic field at a point on the axis at a distance of \(5\;\rm{cm}\) from the centre due to this loop?Ans: Magnitude of the magnetic field at the centre of a circular loop is A straight current-carrying conductor is carrying a current I as shown in the figure. Inversely, it can also be stated that if the thumb represents the direction of current, then the fingers denote the direction of the magnetic field. WebAnimal cognition encompasses the mental capacities of non-human animals including insect cognition.The study of animal conditioning and learning used in this field was developed from comparative psychology.It has also been strongly influenced by research in ethology, behavioral ecology, and evolutionary psychology; the alternative name How many times per second it changes its direction? State your observation for the following cases and give reasons for the same in each case. The degree of closeness of the field lines depends upon the strength of the magnetic field. b) Magnetic field due to a current in a solenoid. Question 29 How does a solenoid behave like a magnet? (2020) (Board Term I, 2014) If we place another current-carrying wire in its vicinity, it experiences a force that is produced by the first current-carrying wire. (d) Why is it necessary to earth metallic electric appliances? A.C. can be transmitted to distant places without much loss of electric power than D.C. That is why A.C. is preferred over D.C. for transmission of current over a long distances. This results in decreasing the efficiency of the circuit. A current is passed through the coil and iron filings are sprinkled on the cardboard. (b) Since magnetic field strength at a point is inversely proportional to the distance from the wire. (i) Moved quickly towards the coil : A current is induced in clockwise direction in the coil with respect to the side facing the north pole of the magnet and needle of galvanometer will deflect in one direction from zero position. Answer: Place the compass near the north pole of magnet and mark the position of needle. Given r = 5m and $\lambda$= 8 $\times$ 10-3 cm. What is solenoid? Write one application of Flemings left hand rule. (Board Term I, 2016) (iii) The role of split ring is to change the direction of current flowing through the coil after each half-rotation of coil. Answer: State whether an alpha particle will experience any force in a magnetic field if (alpha particles are positively charged particles) (a) The direction of magnetic field (B) at any point is obtained by drawing a tangent to the magnetic field line at that point. The magnet so formed is called an electromagnet. 3. (c) length of the conductor Question 39. (a) Fuse acts like a watchman in an electric circuit. ii) The magnetic field lines are closer at the poles. At the time of short circuit, the electric current in the circuit. Question 20. Example 3: Find the electric field at 6m from an infinitely long wire with a linear charge density of 8 x 10-3$\dfrac{C}{m}$. Answer: It is an extremely important topic and has a high chance of being asked in the exam. List two distinguishing features between the two fields. (a) State Right Hand Thumb rule to find the direction of the magnetic field around a current carrying straight conductor. (b) The phenomena involved is called electromag-netic induction. (b) Direction of force will be reversed, if the direction of current is reversed, i.e., the force on the conductor will act from left to right. (i) it is placed in the field at rest. What will you observe in the galvanometer connected across the coil Q Same of current will be induced and the direction of flow of current will also be the same in the two cases. Question 3. (i) Solenoid : A coil of many circular turns of insulated copper wire wrapped in the shape of cylinder is called solenoid. Magnetic field due to straight wire comes under the chapter magnetic effects of current and magnetism. (ii) The current carrying solenoid when suspended freely rests along a particular direction. (d) The strength of electromagnet can be increased by How is the type of current that we receive in domestic circuit different from the one that runs a clock? WebAn electric motor is an electrical machine that converts electrical energy into mechanical energy.Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of torque applied on the motor's shaft. (Board Term I, 2014) Biot Savarts law states the relationship between a current-carrying wire and a point P placed at a distance r from the wire. The magnetic field of all the turns of wire passes through the center of the coil, creating a strong magnetic So, the magnetic field by both wires at point P is 0.25$\times$ 10-6 T. The article presents a thorough walkthrough of the magnetic field for a long infinite straight current carrying wire. And, at the axial point, we have Q.3: Where is the magnetic field due to current through a circular loop uniform?Ans: The magnetic field due to current through the circular loop is uniform at the centre of the current loop and non-uniform near the circular coil. If the forefinger gives the direction of the magnetic field (N to S), the second (middle) finger the direction of current then the thumb gives the direction of the force acting on the conductor. At which distance is the magnetic field 2 $\times$ 10-3 T? As we move towards the centre of the coil, the strength of magnetic field increases. (d) At the time of short circuit, the live and neutral wire come in direct contact, thus increasing the current in the circuit abruptly. (i) When key is closed, after setting up the circuit as shown, one can observe a deflection on the galvanometer connected to the second coil. Similarly a fuse of lower rating may melt frequently even for a normal flow of current. 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