Question

True/False Questions : (IF false give the  reason) 

1. Sound waves are transverse waves by nature. 

2. Longitudinal waves are characterised by compressions and rarefactions.

3. Medium is not required for the propagation of light. 

4. Ultrasonic waves are the waves with a frequency about 20 KHz. 

5. Velocity of sound is the greatest in gas.

6. Velocity of sound in a gas is directly proportional to the square root of its temperature.

 7. According to law of reflection of sound, angle of incidence is equal to angle of reflection. 

8. When sound waves are reflected from a plane surface, the intensity of the reflected wave is neither decreased nor increased. 

9. Ear trumpet works on the principle of reflection of sound. 

10. The principle of SONAR is Doppler effect.

Answer 1

1. False – Sound waves are longitudinal waves by nature. 

2. True 

3. True 

4. False – Ultrasonic waves are the waves with a frequency greater than 20 KHz. 

5. False – Velocity of sound is the least in gas. 

6. True 

7. True 

8. True 

9. False – Ear trumpet works on the principle of reflection of sound. 

10. True