EASY
7th CBSE
IMPORTANT
Earn 100

What is an electromagnet? Give three uses of electromagnets. 

Important Questions on Electric Current and Its Effects

MEDIUM
7th CBSE
IMPORTANT
Living Science 7>Chapter 17 - Electric Current and Its Effects>EXERCISES>Q D
Explain the working of a simple electric bell.
EASY
7th CBSE
IMPORTANT
Living Science 7>Chapter 17 - Electric Current and Its Effects>EXERCISES>Q 1
Fuse wires or miniature circuit breakers are not used in a circuit containing electric cells. Why?
EASY
7th CBSE
IMPORTANT
Living Science 7>Chapter 17 - Electric Current and Its Effects>EXERCISES>Q 2

Can you use a copper wire to make the filament of an electric bulb? Why?

EASY
7th CBSE
IMPORTANT
Living Science 7>Chapter 17 - Electric Current and Its Effects>EXERCISES>Q 3
Mohit used a fuse wire with a specification of 5 amperes in a circuit connected to an air conditioner which draws a current of 10 amperes. What will happen when the air conditioner is switched on? What will you advise him to do?
HARD
7th CBSE
IMPORTANT
Living Science 7>Chapter 17 - Electric Current and Its Effects>EXERCISES>Q 4
Rita used a fuse wire with a 100 amperes specification in a circuit at home which draws a maximum current of 20 amperes when all devices in the circuit are switched on. Do you think she used the correct fuse wire? What will you advise her to do?
 
EASY
7th CBSE
IMPORTANT
Living Science 7>Chapter 17 - Electric Current and Its Effects>EXERCISES>Q 5
You have seen that the heating effect of current can be put to good use. Can you think of situations where this effect results in wastage of energy? 
EASY
7th CBSE
IMPORTANT
Living Science 7>Chapter 17 - Electric Current and Its Effects>EXERCISES>Q 6
A coil with no current passing through it is suspended freely It points in the east—west direction. Explain what will happen if a current is passed through the coil.
 
MEDIUM
7th CBSE
IMPORTANT
Living Science 7>Chapter 17 - Electric Current and Its Effects>EXERCISES>BE A SCIENTIST

Be a scientist. Which of these circuits will the lamp glow when the switch is on? Explain the reason in each case.Question Image