What is fitted in telephone receiver:
Electromagnet
Diaphragm
Both a and b
None
Which of the following is an insulator:
Copper
Iron
Silk
Silver
The speed of sound in a liquid is …………..than that in gases:
Ten times
Fifteen times
Five times
Two times
electroscope can also be charges by the process of:
electrostatics
electricity
convection
conduction
Power of hair dryer is:
1000 W
750 W
10 W
75 W