Question Detail

Marie and Pierre Curie invented

Radio
Radium
Radar
Refrigerator

Answer: Option B

Explanation:

Marie and Pierre Curie of France invented Radium in 1898,

Radio was invented by G. Marconi of England in 1901,

Radar was invented by Dr. A.H. Taylor and L.C. Young of USA in 1922,

Refrigerator was invented by J. Harrison and A. Catlin of Britain in 1834.

1. 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

2. 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.

3. Which is true

In a static liquid at same horizontal level, pressure is more at centre
In a static liquid at same horizontal level, pressure is less at centre.
In a static liquid at same horizontal level, pressure is same at all points
In a static liquid at same horizontal level, pressure is different at all points

Answer: Option C

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

True
False

Answer: Option A

5. 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.