MEDIUM
7th CBSE
IMPORTANT
Earn 100

Draw a well-labelled diagram of a closed electric circuit.

Important Questions on Electric Current and its Effects

MEDIUM
7th CBSE
IMPORTANT

How does an electric current flow in a closed circuit? Explain.

EASY
7th CBSE
IMPORTANT

An electric oven of 3 kW is connected to the mains of 220 V. Calculate:

The amount of energy consumed if the oven is switched on for an hour.

MEDIUM
7th CBSE
IMPORTANT

An electric oven of 3 kW is connected to the mains of 220 V. Calculate:

The cost of electrical energy consumed if the cost per unit is Rs. 6.50 and if the oven is switched on for an hour.

EASY
7th CBSE
IMPORTANT
How much energy is used for boiling water in a 2 kW kettle for 10 minutes? Calculate it in watt-hour.
MEDIUM
7th CBSE
IMPORTANT
A mobile phone is one of the many electrical appliances, which makes use of both the chemical and magnetic effects of an electric current. Can you describe how the mobile phone makes use of these effects?
MEDIUM
7th CBSE
IMPORTANT
In many electrical appliances such as an electric oven, iron, and kettle, an automatic switch is used. The switch automatically switches off when the task is over. How does the automatic switch of these appliances reduce electrical energy wastage?    
EASY
7th CBSE
IMPORTANT

Give reasons for the following.

Birds do not get electrocuted when they perch on power lines.

EASY
7th CBSE
IMPORTANT

Give reasons for the  following:

Nichrome wire is used as a heating element instead of copper wire.