Name three devices which work on the reflection of sound.

What is reflection of sound ?

Name the devices in which total internal reflection of light is used.

(a) Name one device which works on the magnetic effect of current. (b) Name one device which works on the phenomenon of electromagnetic induction. (c) Which device converts electric energy into mechanical energy? (d) Describe the principle of working of an electric motor. (e) Explain the principle of working of an electric generator.

Name one device which works on the magnetic effect of current.

Which of the following device does not work on reflections of sound waves?

(a) What is meant by 'reflection of sound'? What type of surfaces are the best for reflecting sound? (b) Name any two objects which are good reflectors of sound. (c) State the laws of reflection of sound.

What name is given to the repettion of sound caused by the reflection of sound waves?

What is the name of the device which is used to find the depth of sea (or ocean) by using ultrasonic sound waves?