Question Detail

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

1. K. Macmillan invented

Bicycle
Barometer
Calculating Machine
Centigrade Scale

Answer: Option A

Explanation:

K. Macmillan of Scotland invented Bicycle in 1839.

Barometer was invented by E. Torricelli of Italy in 1644.

Calculating Machine was invented by Pascal of France in 1642.

Centigrade Scale was invented by A. Celsius of France in 1742.

2. 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.

3. Who discovered Atom ?

Madam Curie
James Chadwick
Rutherford
John Dalton

Answer: Option D

Explanation:

John Dalton discovered Atom in 1808,

Madam Curie discovered Radium in 1898,

James Chadwick discovered Neutron in 1932,

Rutherford discovered Proton in 1919.

4. If no external force acts on a system of bodies, the total linear momentum of the system of bodies remains constant. Which law states this ?

Newton first law
Newton second law
Newton third law
Principle of conservation of linear momentum

Answer: Option D

5. Radian is used to measure

Temperature
Intensity of Flame
Angle
Solid Angle

Answer: Option C

Explanation:

Kelvin is used to measure Temperature,

Candela is used to measure Intensity of flame,

Steredian is used to measure Solid Angle.