Question Detail

Which of the following is an electromagnetic wave ?

Cathode rays
Sound wave
Ultrasonic wave
Infra red rays

Answer: Option D

1. 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

2. Which are the primary Colours ?

Yellow, Green, Blue
Red, Magenta, Blue
Red, Green, White
Red, Green, Blue

Answer: Option D

Explanation:

Red, Green, Blue are primary colours. All the colours can be produced by them by mixing in different proportions. Interesting :)

3. Which instrument is used to measure altitudes in aircraft's ?

Audiometer
Ammeter
Altimeter
Anemometer

Answer: Option C

Explanation:

Ammeter - Measures strength of electric current.

Audiometer - Measures intensity of sound.

Anemometer - Measures force and velocity of wind and directions.

4. radian per second is unit of

Momentum
Moment of Inertia
Frequency
Angle Velocity

Answer: Option D

Explanation:

unit of Momentum is kilogram meter per second,

unit of Moment of Inertia is kilogram square meter,

unit of frequency is Hertz.

5. 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