12th Class Physics MCQ Test With Answer for Physics Full Book

The effective value of any sinusoidal alternating current or voltage is

• 
  A
• 
  B
• 
  C
• None of the above D

split rings are used in

• A.C. generator A
• A.C. motor B
• Transformer C
• D.C. motor D

Average value of current and voltage over a complete cycle is.

• Positive A
• Negative B
• Zero C
• Infinite D

1 gray is equal to.

• 1 JKg-1 A
• 1KgJ-1 B
• 1JKg C
• 1 JKg-2 D

A metal rod of 1 m is moving at a speed of 1 ms-1 in a direction making an angle 30 ^o with 0.5 T magnetic field . The emf produced is.

• 0.25 N A
• 2.5 N B
• 0.25 V C
• 2.5 V D

Net charge enclosed by Gaussian surface is:

• zero A
• maximum B
• depend on intensity C
• none of all D

The peak value of alternating current is 5√2 A. The mean square value of current will be:

• 5A A
• 2.5A B
• 5√2A C
• 5² D

Insulators have:

• An empty conduction band A
• Al full valence band B
• A large energy gap C
• All of above D

• Lenz's law A
• Faraday's law B
• Ampere's law C
• None of these D

A charged particle having charge 'q' is moving at right angle to magnetic field. The quantity which varies is.

• Speed A
• Kinetic energy B
• Path of motion C
• angular velocity D

The typical nuclei are less than:

• 10^-16m A
• 10^-14m B
• 10^-12m C
• 10^-10m D

If the distance between two charges is halved and charges are also doubled, then force between them will be.

• Two time A
• Four time B
• Eight time C
• Sixteen time D

The SI unit of magnetic permeability is.

• WbA-1m-1 A
• Wbm-2 B
• WbmA-1 C
• WbAm-1 D

Energy stored in inductor is.

• 1/2 L I² A
• 1/2 LI B
• 1/2 L2I C
• 1/2 L2I2 D

In A.C. inductor behaves as

• Capacitor A
• Resistor B
• Commutator C
• Transistor D

The phase difference between the current and voltage at resonce is:

• 0 A
• π B
• -π C
• π/2 D

The critical temperature of mercury is.

• 1.18 K A
• 4.2 K B
• 3.72 K C
• 7.2 K D