MCQ on Electromagnetic Induction and Faraday's Law - Set 03 - ObjectiveBooks

# Practice Test: Question Set - 03

1. The law that the induced e.m.f. and current always oppose the cause producing them is due to
(B) Lenz
(C) Newton
(D) Coulomb

2. An open coil has
(A) Zero resistance and inductance
(B) Infinite resistance and zero inductance
(C) Infinite resistance and normal inductance
(D) Zero resistance and high inductance

3. Find the force acting on a conductor 3m long carrying a current of 50 amperes at right angles to a magnetic field having a flux density of 0.67 tesla
(A) 100 N
(B) 400 N
(C) 600 N
(D) 1000 N

4. If current in a conductor increases then according to Lenz's law self-induced voltage will
(A) Aid the increasing current
(B) Tend to decrease the amount of current
(C) Produce current opposite to the increasing current
(D) Aid the applied voltage

5. As per Faraday's laws of electromagnetic induction, an e.m.f. is induced in a conductor whenever it
(A) Lies perpendicular to the magnetic flux
(B) Lies in a magnetic field
(C) Cuts magnetic flux
(D) Moves parallel to the direction of the magnetic field

6. An e.m.f. of 16 volts is induced in a coil of inductance 4H. The rate of change of current must be
(A) 64 A/s
(B) 32 A/s
(C) 16 A/s
(D) 4 A/s

7. A 500 turns solenoid develops an average induced voltage of 60 V. Over what time interval must a flux change of 0.06 Wb occur to produce such a voltage?
(A) 0.01 s
(B) 0.1 s
(C) 0.5 s
(D) 5 s

8. The self-inductance of the coil may be defined as equal to the e.m.f. induced in volts when the current in the circuit changes at the rate of unit Weber turns.
(A) Yes
(B) No

9. A coil induces 350 mV when the current changes at the rate of 1 A/s. The value of inductance is
(A) 3500 mH
(B) 350 mH
(C) 250 mH
(D) 150 mH

10. A coil with negligible resistance has 50V across it with 10 mA. The inductive reactance is
(A) 50 ohms
(B) 500 ohms
(C) 1000 ohms
(D) 5000 ohms

Show and hide multiple DIV using JavaScript View All Answers

Blogger Comment