# Quiz: 12th Grade Physics Practice Paper!

50 Questions  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

• 26.
Which of the following has a small eyepiece and a large objective lens:
• A.

Telescope

• B.

Compound Microscope

• C.

Simple Microscope

• D.

Periscope

• 27.
What happens below the threshold frequency:
• A.

Partial emission of photoelectrons

• B.

Increase in photoelectric current

• C.

Decrease in photoelectric current

• D.

No emission of photoelectrons

• 28.
What kind of wave are used for line of sight communication:
• A.

Sky Wave

• B.

Sound Wave

• C.

Space Wave

• D.

Light Wave

• 29.
How is the intensity of transmitted light varied when the Polaroid is rotated:
• A.

Intensity doubles

• B.

Intensity becomes half

• C.

Intensity becomes four times

• D.

Intensity remains same

• 30.
Endoscopy is based on the principle of:
• A.

Interference

• B.

Diffraction

• C.

Total Internal Reflection

• D.

Polarisation

• 31.
A charge Q is placed at the centre of the toroid. What will be the current enclosed by the toroid:
• A.

Negative Current

• B.

Zero Current

• C.

Positive Current

• D.

Infinite Current

• 32.
Which of the following will exit the cyclotron first?
• A.

Alpha particle

• B.

Proton

• C.

Deuterium Ion

• D.

Lithium ion

• 33.
Which of the following is vector quantity:
• A.

Current

• B.

Electric Flux

• C.

Electric Potential

• D.

Electric dipole Moment

• 34.
In an equipotential surface:
• A.

Entire charge is concentrated at the centre

• B.

No work is done to bring a test charge to a near charge

• C.

Electric field is in the opposite direction in which the potential decreases

• D.

Electric field due to induced charges opposes the external field within the conductor

• 35.
Which of the following depends on the Inverse Square Law:
• A.

Ampere Circuital Law

• B.

Lenz Law

• C.

Snell’s Law

• D.

Gauss Law

• 36.
Which of the following is dynamically stable in a hydrogen atom:
• A.

Centrifugal Force

• B.

Vander Waal’s Force

• C.

Centripetal Force

• D.

Gravitational Force

• 37.
According to Bohr, what kind of spectrum would be emitted when an accelerating electrons revolves around the  nucleus:
• A.

Line

• B.

Continuous

• C.

• D.

Zigzag

• 38.
Which of the following have a high binding energy:
• A.

Iron

• B.

Zinc

• C.

Aluminium

• D.

Uranium

• 39.
The source of energy in sun and stars is:
• A.

Fission

• B.

Photon Energy

• C.

Combustion

• D.

Fusion

• 40.
Neutrino detection is difficult because:
• A.

They have weak interaction with other particles

• B.

They have strong interaction with other particles

• C.

They have nuclear interaction with other particles

• D.

They have ion-ion interaction with other particles

• 41.
Paschen series lies in which region?
• A.

Visible

• B.

Ultraviolet

• C.

Infrared

• D.

Microwave

• 42.
Which of the following have a magnitude but not direction:
• A.

Velocity

• B.

Magnetic Field

• C.

Current

• D.

Force

• 43.
Which of the following will not show polarisation:
• A.

Ultrasonic Wave

• B.

Light Wave

• C.

Micro Wave

• D.

• 44.
Linearly polarized light only vibrate in:
• A.

Two plane

• B.

One plane

• C.

Four plane

• D.

No plane is involved

• 45.
The S.I. Unit for current sensitivity is:
• A.

Ampere

• B.

Ampere (metre)

• C.

(Ampere)-1

• D.

Ampere (metre)-1

• 46.
The Square Law Device is a:
• A.

Linear Device

• B.

Closed Device

• C.

Non-Linear Device

• D.

Open Device

• 47.
To what phenomenon the decay of light bulb be compared to:
• A.

• B.

Activity Of Sample

• C.

Mean Life

• D.

• 48.
The angle between the true geographic north and the magnetic north is called:
• A.

Magnetic declination

• B.

Angle of dip

• C.

Dynamo Effect

• D.

Gyro-magnetic angle

• 49.
The galvanometer do not show any deflection if:
• A.

Bridge current flow to be constant

• B.

Bridge voltage to be constant

• C.

Bridge is balanced

• D.

Bridge resistance is constant

• 50.
Which of the following is based on conservation of charge:
• A.

Kirchhoff’s Junction Rule

• B.

Kirchhoff’s Voltage Law

• C.

Ohm’s Law

• D.

Biot-Savart Law