CBSE Physics Electromagnetic Induction Test Online

1. The current in self-inductance L = 40 Hm is to be increased uniformly form 1 A to 11 A in 4 milliseconds. The emf induced in inductor during the process is ?

2. Eddy currents are produced when ?

3. A long solenoid has 500 turns. When a current of 2 A is passed through it, the resulting magnetic flux linked with each truth of the solenoid is 4 x 10^-3 Wb. The self-inductance of the solenoid is ?

4. If N is the number of turns is a coil, the value of self-inductance varies as ?

5. A conductor of length 0.4 m is moving with a speed of 7 m/s perpendicular to a magnetic field of intensity 0.9 Wb/m². The induced emf across the conductor is ?

6. Energy in a current carrying coil is stored in the form of

7. A conducting circular loop is placed in a uniform magnetic field 0.04 T with its plane perpendicular to the magnetic field. the radius of the loop starts shrinking at 2 mms^-1. The induced emf in the loop when the radius is 2 cm is ?

8. The magnetic flux through a circuit of resistance R changes by an amount ΔΦ in a time Δt. Then the total quantity of electric charge q that passes any point in the circuit during the time Δt is represented by ?

9. A 100 mH coil carries a current of 1 A. Energy stored in its magnetic field is ?

10. The total charge induced in a conducting loop when it is moved in magnetic field depends on ?

11. Two coils have a mutual inductance of 0.005 H. The current changes in the first coil according to equation i = i_° sin ωt, i_° = 10 A  and ω = 100 π rad/s. The maximum value of emf in the second coil is ?

12. A rectangular coil of 20 turns and area of cross section 25 sq cm has a resistance of 100Ω. If a magnetic field which is perpendicular to the plane of coil changes at a rate of 100 t/s,the current in the coil is ?

13. As a result of change in the magnetic flux linked to the closed loop shown in the figure, an emf V volt is induced in the loop. The work done (joules) in taking a charge q coulomb once along the loop is ?

14. Two coils of self-inductance 2 mH and 8 mH are placed so close together that the effective flux in one coil is completely linked with the other. The mutual inductance between theses coils is ?

15. In an inductor of self-inductance L  = 2 mH, current changes with time according to relation i = t²e^-t. At what time emf is zero ?