TNSB +2 Physics (Trial)

1. Stars which appear single to the naked eye but are double when seen through a telescope are

Novas and supernovas

Binaries

Asteroids

Quasars

Actually at very far distances, resolving power of our eye becomes very very weak.

Explanation

Actually at very far distances, resolving power of our eye becomes very very weak.

2. Radiocarbon is produced in the atmosphere as a result of

Collision between fast neutrons and nitrogen nuclei present in the atmosphere

Action of ultraviolet light from the sun on atmospheric oxygen

Action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere

Lightning discharge in atmosphere

The neutrons these are produced in atmosphere from the sun radiation i.e.cosmic rays. So that the obtained neutron is then reacts with the nitrogen which is present in the atmosphere and produce radioactive element

Explanation

The neutrons these are produced in atmosphere from the sun radiation i.e.cosmic rays. So that the obtained neutron is then reacts with the nitrogen which is present in the atmosphere and produce radioactive element

3. Mica is used in electrical appliances such as electric iron because mica is

A good conductor of heat but a bad conductor of electricity

A bad conductor of heat but a good conductor of electricity

A good conductor of heat as well as electricity

A bad conductor of heat as well as electricity

Mica is a good conductor of heat but a bad conductor of electricity, mica heats the iron's base but not give electric shock. That's why it is use in electric iron.

Explanation

Mica is a good conductor of heat but a bad conductor of electricity, mica heats the iron's base but not give electric shock. That's why it is use in electric iron.

4. If the distance between two masses is increased by a factor of 4, the gravitational force of attraction between them will

Reduce by a factor of 16

Remain Same

Reduce by a factor of 4

Increase by a factor of 4

The gravitational force between two bodies is given by F =

Explanation

The gravitational force between two bodies is given by F =

5. Sound produced at a point is heard by a person after 5 second, while the same sound is heard by another person after 6 seconds. If the speed of sound is 300 m/s, what could be the maximum and minimum distances between the two persons?

1.8 km, 0.15 km

2.2 km, 0.20 km

2.8 km, 0.25 km

3.3 km, 0.30 km

DISTANCE = SPEED * TIME TAKEN

d1=300*5=1500

d2=300*6=1800

maximum distance=d1+d2=3300 metres=3.3km

minimum distance=d2-d1=1800-1500=300 metres=0.3km

Explanation

DISTANCE = SPEED * TIME TAKEN

d1=300*5=1500

d2=300*6=1800

maximum distance=d1+d2=3300 metres=3.3km

minimum distance=d2-d1=1800-1500=300 metres=0.3km

6. A particle is executing simple harmonic motion with frequency f. The frequency at which its kinetic energy change into potential energy is

F/2

F

2f

4f

In Simple Harmonic Motion, frequency of K.E. and P.E. = 2 * (Frequency of oscillating particle)

Explanation

In Simple Harmonic Motion, frequency of K.E. and P.E. = 2 * (Frequency of oscillating particle)

7. A cannonball is fired horizontally at 10 m/s from a cliff. Its speed one second after being fired is about

10m/s

14m/s

16m/s

20m/s

14m/s is correct, as vector addition shows if a student knows that gain of vertical speed in 1 s is 10 m/s.

Explanation

14m/s is correct, as vector addition shows if a student knows that gain of vertical speed in 1 s is 10 m/s.

8. Out of the following pairs, choose the pair in which the physical quantities do not have identical dimension?

Pressure and Young's modules

Planck's constant and Angular momentum

Impulse and moment of force

Force and rate of change of linear momentum

Impulse means change in the momentum of a body,Impulse = Ft = mv - mu The turning effect of force about the axis of rotation is called moment of force or torque.

So they don't have any units... resulting no dimensions!!

Explanation

Impulse means change in the momentum of a body,Impulse = Ft = mv - mu The turning effect of force about the axis of rotation is called moment of force or torque.

So they don't have any units... resulting no dimensions!!

9. Moment of inertia is

Vector

Phasor

Scalar

Tensor

Moment of inertia is prodct of mass and squre of radius[that is tensile strength] ie I=mc^2

Explanation

Moment of inertia is prodct of mass and squre of radius[that is tensile strength] ie I=mc^2

10. Lux is the SI unit of

Intensity of illumination

Luminous efficiency

Luminous flux

Luminous intensity

The SI unit of intensity of illumination (illuminance) is the lux. An illuminance of 1.0 lux is produced by 1.0 lumen of light shining on an area of 1.0 m^2.

Explanation

The SI unit of intensity of illumination (illuminance) is the lux. An illuminance of 1.0 lux is produced by 1.0 lumen of light shining on an area of 1.0 m^2.

Tnsb +2 Physics (Trial)