Calculate the mutual inductance of a 1 m long coil with 0.4 m radius and 1000 turns has a secondary of 500 turns wound near its mid-point. If no magnetic materials are present, the magnetic field produced by a coil, and hence also the flux, are directly proportional to the current flowing through it. 4.18. This document is highly rated by Class 12 students and has been viewed 2948 times. You may need to download version 2.0 now from the Chrome Web Store. L = 2200 H. Therefore, the self-inductance of the coil is 2200 H. See figure 12. The inductance value is of two types. • Self Inductance Electromagnetic Induction of Class 12 It is convenient to express the induced emf in terms of the current in a circuit rather than the magnetic flux through it. Calculate the mutual inductance of the system? M 12 =M 21. L =( μ_0 μ_r N 2 A)/l. Total flux: -N1xBxA1=N1x(μ0xN1I/2πr1) x A1, = (4πx10-7x (1200)2x 2x10-4)/ (2πx15x10-2). If you are on a personal connection, like at home, you can run an anti-virus scan on your device to make sure it is not infected with malware. What is the unit of Self Inductance? Therefore, to find out the self-inductance of the coil, we apply the equation of inductance which is: L = ΦN/I. The inductance value is represented as L and its unit is Henry. Establish the relation between self inductance and mutual inductance of two coils. The emf induced in the second coil is 0.023V. Because of the increase in the flux linked with the coil1, the flux of coil 2 also increases. When the key is pressed attached to the coil 1 the current starts flowing, when the current starts increasing flux linked also starts increasing. L = (20 Wb)(550)/5A. self-inductance. The proportionality constant is the After some time, no effect of self inductance remains in the coil because after certain time the current becomes steady. The self-inductance of a circuit depends on the size and shape. where µr = Relative magnetic permeability of magnetic material, µr =μ/μ_0 . all rights reserved. One is the mutual inductance and another one is self-inductance. Answer- We see that we have Φ as 20 Wb and N is 550. What will be the effect on self inductance when the number of coils is doubled? If the current carried by the solenoid changes steadily from 2.0 A to 4.0A in 0.1 s, what is the induced emf in the loop while the current is changing? Obtain the self-inductance of the toroid. Here µ0 = 4π × 10-7 H/m; N = 100 ; A = 5 × 10-4 m2 ; l = 0.1 m, Important Questions CBSE Class 10 Science. 3. (a) Define the term 'self-inductance' and write its S.I. QnA , Notes & Videos (b) A second coil of 300 turns is wound closely on the toroid above. Define. In essence, the directi… Performance & security by Cloudflare, Please complete the security check to access. Problem:- A long solenoid with 15 turns per cm has a small loop of area 2.0 placed inside the solenoid normal to its axis. A = Area of cross-section of solenoid . There are two types of inductance: self inductance and mutual inductance. As expected, the flux is proportional to the current I. What is the difference between self inductance and mutual inductance? Find the self inductance of a solenoid of length 10 cm, area 5 cm2 and number of turns 100. You may need to download version 2.0 now from the Chrome Web Store. Performance & security by Cloudflare, Please complete the security check to access. •The magnetic flux produced by the current in the coil is linked with the coil itself. For example, size, length, number of turns etc. And question 4. Therefore change in current in the solenoid, di = 4 – 2 = 2 A. Find out the self-inductance of the coil. A-1, Acharya Nikatan, Mayur Vihar, Phase-1, Central Market, New Delhi-110091. Your IP: 46.254.16.171 Detailed explanation with examples on self-inductance helps you to understand easily , designed as per NCERT. • Learn the concepts of Class 12 Physics Electromagnetic Induction with Videos and Stories. Your IP: 144.91.112.219 Another way to prevent getting this page in the future is to use Privacy Pass. Current is induced in the same coil. Self inductance is the property of a coil which opposes the change in current through it. What is the length of a solenoid with total number of turns 1000, area of cross section 20 cm 2 and self inductance of 4.02 × 10-3 H. Induced emf in the solenoid is given by Faraday’s law as: Where, Φ= Induced flux through the small loop, Hence, the induced voltage in the loop is 7.54x10-6V, Varying Area A in a closed loop with movable piston, Varying angle between magnetic field and area vector, Class 12 Physics Electromagnetic Induction. • Oct 14, 2020 - Self-Inductance Class 12 Notes | EduRev is made by best teachers of Class 12. Ignore field variations across the cross-section of toroid. Current tries to oppose the change in the flux. Self inductance, L is a geometric quantity; it depends only on the dimensions of the solenoid, and the number of turns in the solenoid. What is the difference between self inductance and mutual inductance? Give N (fi_B) = LI. Because of the induced emf induced current will be there in coil2. where n = is the number of turns per unit length, N the total number of turns, l the total length, and I the current in the solenoid. It is convenient to express the induced emf in terms of the current in a circuit rather than the magnetic flux through it. To a good approximation, the magnetic field inside the solenoid is uniform and given by. If the current in the primary coil is increased from 0 to 2A in 0.05s.Obtain the induced emf in the second coil. Self inductance - definition Self inductance is defined as the induction of a voltage in a current-carrying wire when the current in the wire itself is changing. •When an electric current is passed through an insulated conducting coil, it gives rise to a magnetic field in the coil so that the coil itself behaves like a magnet. Please solve question 2  Varying Area A in a closed loop with movable piston, Varying angle between magnetic field and area vector, Class 12 Physics Electromagnetic Induction. Explain self inductance. Another way to prevent getting this page in the future is to use Privacy Pass. Copyright © 2020 Entrancei. If you are at an office or shared network, you can ask the network administrator to run a scan across the network looking for misconfigured or infected devices. Answer: - Number of turns on the solenoid = 15 turns/cm = 1500 turns/m, Number of turns per unit length, n = 1500 turns, The solenoid has a small loop of area, A =2.0 cm2= 2 × 10-4m2. self inductance 1. Therefore Self-inductance will describe about the ratio of magnetic flux to the current it induces. What is coefficient of coupling given L 1 = 4 H , L 2 = 4 H , M = 256. unit. All rights reserved. Formula for Inductance $$L=\mu N^2A/l$$ Where Completing the CAPTCHA proves you are a human and gives you temporary access to the web property. Where L is a constant of proportionality called the self-inductance of the coil. Calculate the mutual inductance of a 1 m long coil with 0.4 m radius and 1000 turns has a secondary of 500 turns wound near its mid-point. M 12 = (μ 0 N 1 N 2 A 2)/l ength =μ 0 n 1 n 2 A 2 l ength =4x3.14x10-7 x2000x2500x50x10-2 x25x10-4 =7.85x10-3 H. Problem:- (a) A toroidal solenoid with an air core has an average radius of 15cm, area of cross-section 2cm 2 and 1200 turns. SELF INDUCTANCE 2. Using Faraday's law the induced emf in the coil is given by. If you are on a personal connection, like at home, you can run an anti-virus scan on your device to make sure it is not infected with malware. Derive L = u_r (u_0) n^2Al. Mutual Inductance between long co-axial solenoids. The polarity of the emf depends on the rate of change of the current, not on its magnitude or its direction. Answer:- Let the outer solenoid be 1 and inner solenoid be 2. In simple terms, we can also say that self-inductance is a phenomenon where there is the induction of a voltage in a current-carrying wire. Want a call from us give your mobile number below, For any content/service related issues please contact on this number. (b) Obtain the expression for the mutual inductance of two long co-axial solenoids S 1 and S 2 wound one over the other, each of length L and radii r 1 and r 2 and n 1 and n 2 number of turns per unit length when a current I … Calculate the mutual inductance if the radius of circular coil is 'r' with 'n' number of turns kept at distance 'l' from the conductor. Suppose a circular coil and a conductor are kept adjacent to each other in same plane. The self-inductance of the toroid is 2.304x10-4 H. (dI1/ dt) = (If –Ii)/dt = (2-0)/ (0.05) =40A/s. Self-inductance is the property of the current-carrying coil that resists or opposes the change of current flowing through it. Derive emf e and back emf. Further, I is 5 A. Its SI unit is henry (H). l = Length of solenoid Clearly, the self-induced emf always opposes the change (increase or decrease) of current in the coil. Current carried by the solenoid changes from 2 A to 4 A. This induced current opposes the increase of the current in coil 1. Suppose there is N number of turns in the coil.Therefore flux linkage of the coil N Φ∝ I. N Φ =LI where L=constant of proportionality and is known as self-inductance. Copyright Notice © 2020 Greycells18 Media Limited and its licensors.