# Quiz: 12th Grade Physics Practice Paper!

50 Questions | Total Attempts: 969  Settings  .

Related Topics
• 1.
What would be the electric flux due to two charges one at the origin of the Gaussian sphere and another at a distance of 4b from origin. Let the radius of the Gaussian sphere be 3b and the charge be Q.
• A.
• B.
• C.
• D.

0

• 2.
What happens to mutual inductance of pair of coils when distance between the coils is increased:
• A.

Mutual Inductance of first coil will increase with decrease in second coil

• B.

Mutual Inductance of both the coils increases

• C.

Mutual Inductance of both the coils decreases

• D.

Mutual Inductance of second coil will increase with decrease in first coil

• 3.
For a semiconductor a negative resistance could found during a:
• A.

Negative Slope

• B.

Positive Slope

• C.

Constant Slope

• D.

Variable Slope

• 4.
What would be the current through the resistance  which is connected to three voltage source  connected in parallel to each other:
• A.
• B.
• C.
• D.
• 5.
What is the reason for the damping of copper plate when it is allowed to oscillate in between the two magnetic poles:
• A.

Polarisation

• B.

Eddy Current

• C.

Amplitude Modulation

• D.

Stationary Waves

• 6.
What is the S.I. Unit of Radioactivity:
• A.

Newton

• B.

Curie

• C.

Becquerel

• D.

Joule

• 7.
Welders wear special goggles to protect their eyes from:
• A.

Ultraviolet Rays

• B.

Infrared Rays

• C.

Microwaves

• D.

Cosmic Rays

• 8.
De Broglie waves associated with a football is not visible because:
• A.

Velocity of the football

• B.

Weight of the football

• C.

Density of the football

• D.

Mass of the football

• 9.
When does a transistor act as a switch:
• A.

Collector current is kept constant

• B.

Collector current is increases

• C.

Collector current is zero

• D.

Collector current decreases

• 10.
What is used to converge the light beam at a single point on the screen during diffraction:
• A.

Polaroid

• B.

Converging Lens

• C.

Diverging Lens

• D.

Prism

• 11.
When a dielectric medium is introduced in between a capacitor, the capacitance:
• A.

Increases

• B.

Decreases

• C.

Constant

• D.

Becomes Negative

• 12.
If the capacitor is being charged by an external ac source with an instantaneous current of I0 cos ωt. The displacement current would be:
• A.
• B.
• C.
• D.
• 13.
In which phenomenon the electrons move with an average velocity which is independent of time, although the electrons are accelerated:
• A.

Resistivity

• B.

Photoelectric Effect

• C.

Drift Velocity

• D.

Interference

• 14.
For drift velocity the electrons move from:
• A.

Low potential to high potential

• B.

High potential to low potential

• C.

Negative potential to zero potential

• D.

Positive potential to zero potential

• 15.
A potentiometer is not affected by the internal resistance of the source because:
• A.

The internal resistance of a given cell is fixed

• B.

One of the cells is chosen as a standard cell whose emf is known to a high degree of accuracy

• C.

• D.

It draws no current from the voltage source being measured

• 16.
The air bubble inside water acts as a _____ lens
• A.

Diverging or Concave

• B.

Plane Mirror

• C.

Converging or Convex

• D.

Bi-Convex

• 17.
A+B = Y denotes which Gate:
• A.

NAND Gate

• B.

OR Gate

• C.

NOR Gate

• D.

AND Gate

• 18.
The condition for maximum power dissipation is:
• A.
• B.
• C.
• D.
• 19.
What would be the resistance of the light bulb rated at 100 W for 220 V ac supply:
• A.

280 Ω

• B.

465 Ω

• C.

382 Ω

• D.

484 Ω

• 20.
What will happen if an open circuit is used in place of the closed loop?
• A.

Flux is induced at the centre of the circuit

• B.

Flux is induced at only one of the ends of the circuit

• C.

Flux is induced across the open ends of the circuit

• D.

Flux is induced for a short period of time

• 21.
If £ is the emf induced between axle and the rim of a wheel. What is the effect on emf if number of spokes were increased?
• A.

Emf is doubled

• B.

No change in Emf

• C.

Emf becomes half

• D.

Emf becomes 4 times

• 22.
Device used only to check the flow of current in a circuit:
• A.

Voltmeter

• B.

Wheatstone Bridge

• C.

Potentiometer

• D.

Galvanometer

• 23.
Current is flowing from east to west in a wire AB. What would be the direction of the flow of current in a wire CD parallel to AB:
• A.

East to West

• B.

North to South

• C.

West to East

• D.

South to North

• 24.
Name the semiconductor device which works under the reverse bias condition:
• A.

Solar Cell

• B.

Zener Diode

• C.

Transistor

• D.

Microprocessor

• 25.
In a diode, what happens at critical voltage:
• A.

Zener Breakdown

• B.

Saturation Current Flow

• C.

Avalanche Breakdown

• D.

Recombination of Charges Occur