Question Detail

Who discovered Diode Bulb ?

Henry Becquerel
Sir J.S. Fleming
Lee De Forest
Archemedes

Answer: Option B

Explanation:

Sir J.S. Fleming discovered Diode Bulb in 1904,

Lee De Forest discovered Triode Bulb in 1906,

Archemedes discovered laws of floatation in 1827,

Henry Becquerel discovered Radioactivity in 1896.

1. The force which opposes the relative motion between different layers of liquid or gases is called

Critical Velocity
Streamline Flow
Terminal Velocity
Viscous Force

Answer: Option D

Explanation:

Critical Velocity - The maximum velocity upto which fluid motion is streamline is called Critical Velocity.

Streamline Flow - If velocity of all fluid particles is same all the time then it can be said in streamline flow.

Terminal Velocity - When a body falls in viscous medium, its velocity first increases and finally becomes constant. The constant velocity is called terminal velocity.

2. unit of Pressure is

newton second
pascal
watt
newton per meter

Answer: Option B

Explanation:

newton second is unit of impulse,

watt is unit of Power,

newton per meter is unit of Surface Tension.

3. Radiocarbon is produced in the atmosphere as a result of

collision between fast neutrons and nitrogen nuclei present in the atmosphere
action of ultraviolet light from the sun on atmospheric oxygen
action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere
lightning discharge in atmosphere

Answer: Option A

4. Alfred Nobel invented

X ray
Diesel Engine
Dynamite
Dynamo

Answer: Option C

Explanation:

Alfred Nobel if Sweden invented Dynamite in 1867,

X ray was invented by Wilhelm Roentgen of Germany in 1895,

Diesel Engine was invented by Rudolf Diesel of Germany 1892,

Dynamo was invented by Michael Faraday of England in 1831.