If a charge in current of 0.01 A in one coil produces a change in magnetic flux
If a charge in current of 0.01 A in one coil produces a change in magnetic flux of 1.2 x 10⁻² Wb in the outer coil, then the mutual inductance of the coils in henry […]
Questions
The current in a self-inductance L=40 mH is to be increased uniformly from 1A to 11 A
The current in a self-inductance L=40 mH is to be increased uniformly from 1A to 11A in 4 ms. The emf indued in the inductor during the process is
Options
(a) 100 V (b) […]
Magnetic flux φ (in weber) linked with a closed circuit of resistance 10 Ω varies
Magnetic flux φ (in weber) linked with a closed circuit of resistance 10 Ω varies with time t (in sec) as φ=5t²-4t+1. The induced e.m.f. in the circuit at 0.2 sec is
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A very small circular loop of radius a is initially (at t=0) coplanar and concentric
A very small circular loop of radius a is initially (at t=0) coplanar and concentric with a much larger fixed circular loop of radius b. A constant current I flows in the larger loop. The […]
Find out the e.m.f. produced when the current changes from 0 to 1 A in 10 sec.
Find out the e.m.f. produced when the current changes from 0 to 1 A in 10 sec. Given L=10 µH.
Options
(a) 1 V (b) 1 µV (c) 1 mV (d) 0.1 V
The initial rate of increase of current, when a battery of emf 6 V is connected
The initial rate of increase of current, when a battery of emf 6 V is connected in series with an inductance of 2H and resistance 12Ω, is
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(a) 0.5 As⁻¹ (b) 1 […]
Large transformers, when used for some time, become hot and are cooled by circulating
Large transformers, when used for some time, become hot and are cooled by circulating oil. The heating of transformer is due to
Options
(a) Both the hysterisis loss and heating effect of current […]
The identical loops of copper and aluminium are moving with the same speed
The identical loops of copper and aluminium are moving with the same speed in a magnetic field. Which of the following statements is true?
Options
(a) Induced emf and induced current are same […]
Changing magnetic fields can set up current loops in nearby metal bodies
Changing magnetic fields can set up current loops in nearby metal bodies and the currents are called as
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(a) eddy currents (b) flux currents (c) alternating currents (d) leaking currents
Correct Answer: […]
The phase difference between the flux linked with a coil rotating in a uniform
The phase difference between the flux linked with a coil rotating in a uniform magnetic field and induced emf produced in it is
Options
(a) π/2 (b) π/3 (c) (-π/6) (d) π
Correct Answer: […]