Question Detail

Which of the following is an electromagnetic wave ?

Cathode rays
Sound wave
Ultrasonic wave
Infra red rays

Answer: Option D

1. What is Hooke's Law ?

Stress is inversely proportional to strain.
Stress is directly proportional to strain.
Stress and strain are dependent on each other.
Stress and strain are independent of each other.

Answer: Option B

2. Alexander Graham Bell invented

Telephone
Telescope
Television
Tank

Answer: Option A

Explanation:

Alexander Graham Bell of USA invented Telephone in 1876,

Telescope was invented by Hans Lippershey of Netherlands in 1608,

Television was invented by John Logie Bared of Scotland in 1926,

Tank was invented by Sir Ernest Swington of England in 1914.

3. Which law states, "The rate of loss of heat by a body is directly proportional to the difference in temperature between the body and the surroundings."

Doppler's Effect
Newton's law of cooling
Kirchhoff's Law
Stefan's Law

Answer: Option B

Explanation:

Doppler's Effect - The Doppler effect can be described as the effect produced by a moving source of waves in which there is an apparent upward shift in frequency for observers towards whom the source is approaching and an apparent downward shift in frequency for observers from whom the source is receding.

Kirchhoff's Law - Kirchhoff's Law signifies that good absorbers are good emitters.

Stefan's Law - The radiant energy emitted by a black body per unit area per unit time is directly proportional to the fourth power of its absolute temperature.

4. Orbital speed of a satellite is dependent of its mass.

True
False

Answer: Option B

Explanation:

Orbital speed of a satellite is independent of its mass.

5. David Hughes invented

Machine Gun
Microphone
Microscope
Motorcycle

Answer: Option B

Explanation:

David Hughes of USA invented Microphone in 1878,

Machine Gun was invented by Richard Gatling of USA in 1861,

Microscope was invented by Z. Jansen of Netherlands in 1590,

Motorcycle was invented by Edward Butler of England in 1884.