Question Detail

What are audible sound waves ?

Having frequency less than 20 Hz
Having frequency between 20 Hz to 20000 Hz
Having frequency more than 20000 Hz
None of above

Answer: Option B

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. 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. Which of following in not a property of cathode ray.

Cathode rays are invisible and travel in a straight line.
These rays can ionise gases.
These rays can penetrate through thin metal foils.
These rays make materials cool on which they fall.

Answer: Option D

Explanation:

These rays heat the materials on which they fall.

4. 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.

5. 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.