Question Detail

Force of attraction between the molecules of different substances is called

Surface tension
Cohensive force
Adhesive force
None of above

Answer: Option C

Explanation:

Cohensive force - Force of attraction between the molecules of same substance is called Cohensive force.

1. Which instrument is used to measure curvature of spherical objects ?

Spectroscope
Spherometer
Spectrometer
Sextant

Answer: Option B

Explanation:

Spectroscope - used to record spectra,

Spectrometer - used to measure the position of spectral lines,

Sextant - used to measure the height of very distant objects and also used by navigators to find the latitude. what you thought :)

2. Which are the primary Colours ?

Yellow, Green, Blue
Red, Magenta, Blue
Red, Green, White
Red, Green, Blue

Answer: Option D

Explanation:

Red, Green, Blue are primary colours. All the colours can be produced by them by mixing in different proportions. Interesting :)

3. Atom is the smallest part of matter which takes part in chemical reactions.

True
False

Answer: Option A

4. 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