Physics quiz for grade 12

The induced emf is maximum if the conductor cuts the magnetic field at:

• A. 0 degree

• B. 45 degree

• C. 90 degree

• D. 30 degree

The device that can be used as a voltage regulator, voltage clamper and a voltage refernce is ___________________.

• Zener diode

• Transistor

• Integrated Circuit

• Resistor

Magnetic permeability is maximum for --------- material.

• A. Dimagnetic

• B. Paramagnetic

• C. Ferromagnetic

• D. None of the above

By which law, the direction of induced emf will be identified?

• A. Faraday’s first law of electromagnetic induction

• B. Faraday’s first law of electromagnetic induction

• C. Lenz’s law

• D. Fleming’s left hand rule

In Fleming’s left hand rule thumb always represents direction of:

• A. Current flow

• B. Induced emf

• C. Magnetic field

• D. Mechanical force

The forward biased resistance of the diode is ...............than its reverse biased resistance.

• larger

• double

• smaller

• none of these

If dopping in the P region is high then N region:

• Depletion layer will more towards P.

• Depletion region will more towards N.

• Depletion region will remain unchanged.

• None of these

Which law states that the magnitude of the induced e.m.f is directly proportional to the rate of change of flux linkage?

• A. Lenz’s law

• B. Faraday’s first law of electromagnetic induction

• C. Lenz’s law

• D. Fleming’s left hand rule

Two coils X and Y are placed in a circuit such that a current changes by 2 a in coil X and the magnetic flux changes of 0.4 Wb occurs in coil Y. The mutual inductance of the coil is:

• A. 0.2 H

• B. 1.6 H

• C. 0.05 H

• D. 0.8 H

Fleming’s left hand rule does not indicate

• A. The direction of current flow in the conductor

• B. The voltage in the conductor

• C. The direction of magnetic field

• D. The direction of the conductor