Latest Physics General Knowledge(GK) Questions and answers

1 .

Suitable impurities are added to a semiconductor depending on its use. This is done in order to

A)

increase its life

B)

enable it to withstand higher voltages

C)

increase its electrical conductivity

D)

increase its electrical resistivity

Correct Answer : increase its electrical conductivity

2 .

Inside an aeroplane, flying at a high altitude,

A)

the pressure is the same as that outside

B)

normal atmospheric pressure is maintained by the use of air pumps

C)

the pressure inside is less than the pressure outside

D)

normal humidity and partial vacuum are maintained

Correct Answer : normal atmospheric pressure is maintained by the use of air pumps

3 .

On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because

A)

mercury is a metal

B)

density of mercury is greater than that of water

C)

cohesion of mercury is greater than its adhesion with glass

D)

cohesion of water is greater than its adhesion with glass

Correct Answer : cohesion of mercury is greater than its adhesion with glass

4 .

Sound of frequency below 20 Hz is called

A)

audio sounds

B)

infrasonic

C)

ultrasonic

D)

supersonics

Correct Answer : infrasonic

5 .

Of the four locations mentioned below the highest inside temperature will be attained in the pressure cooker operated with the pressure valve open

A)

at sea level

B)

at the top of Mt. Everest

C)

at a place in a valley below sea level

D)

in an aeroplane flying at a height of 10,000 m with inside pressure maintained at the sea level

Correct Answer : at a place in a valley below sea level

6 .

RADAR is used for

A)

locating submerged submarines

B)

receiving a signals in a radio receiver

C)

locating geostationary satellites

D)

detecting and locating the position of objects such as aeroplanes

Correct Answer : detecting and locating the position of objects such as aeroplanes

7 .

Intensity of sound at a point is ____ its distance from the source.

A)

directly proportional to

B)

inversely proportional to

C)

directly proportional to square of

D)

inversely proportional to square of

Correct Answer : inversely proportional to square of

8 .

Materials for rain-proof coats and tents owe their water-proof properties to

A)

surface tension

B)

viscosity

C)

specific gravity

D)

elasticity

Correct Answer : surface tension

9 .

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?

A)

1.8 km, 0.15 km

B)

2.2 km, 0.20 km

C)

2.8 km, 0.25 km

D)

3.3 km, 0.30 km

Correct Answer : 3.3 km, 0.30 km

10 .

Point A is at a lower electrical potential than point B. An electron between them on the line joining them will

A)

move towards A

B)

move towards B

C)

move at right angles to the line joining A and B

D)

remain at rest

Correct Answer : move towards B