Question Detail

What is escape velocity ?

Escape velocity is the maximum velocity with which a body should be projected from the surface of earth so it do not go beyond gravitational field of earth.
Escape velocity is the minimum velocity with which a body should be projected from the surface of earth so it do not go beyond gravitational field of earth.
Escape velocity is the minimum velocity with which a body should be projected from the surface of earth so as it goes out of gravitational field of earth and never return to earth.
Escape velocity is the maximum velocity with which a body should be projected from the surface of earth so as it goes out of gravitational field of earth and never return to earth.

Answer: Option C

1. Which instrument is used to measure sound under water ?

Hygrometer
Hygroscope
Hypsometer
Hydrophone

Answer: Option D

Explanation:

Hygrometer - is used to measure level of humidity,

Hygroscope - shows the changes in atmospheric humidity,

Hypsometer - is used to determine the boiling points of liquids.

2. What is the relation between wavelength, frequency and velocity ?

velocity of wave = frequency * wavelength
velocity of wave = frequency/wavelength
velocity of wave = wavelength/frequency
None of above

Answer: Option A

3. What is unit of Astronomical distance ?

light year
angstrom
weber
lux

Answer: Option A

Explanation:

angstrom is used to measure wave length,

weber is used to measure Magnetic flux,

lux is used to measure Intensity of illumination.

4. When a body is immersed partly or wholly in a liquid, there is an apparent loss in weight of the body which is equal to the weight of liquid displaced by the body.

True
False

Answer: Option A

Explanation:

TRUE, it is Archimedes Principle.

5. What is refractive index ?

it is defined as the ratio of speed of light in the medium to the speed of light in vacuum.
it is defined as the ratio of speed of light in vacuum to the speed of light in the medium .
it is defined as the product of speed of light in medium and in vacuum.
None of above

Answer: Option B