MEDIUM
7th CBSE
IMPORTANT
Earn 100

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?

Important Questions on Electric Current and its 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

When four identical electric bulbs are connected as shown in figure A, they glow with normal brightness. Which of the following statements is correct when these bulbs are connected as shown in figure B?

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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.

EASY
7th CBSE
IMPORTANT

Observe the given diagram and answer the question that follows.

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Which effect of electricity is used?

MEDIUM
7th CBSE
IMPORTANT

Observe the given diagram and answer the question that follows.

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How is the temperature adjusted when we rotate the knob while using an electric iron on different fabrics? 

EASY
7th CBSE
IMPORTANT

Observe the given diagram and answer the question that follows.

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What will happen if the brass layer and iron layer is interchanged in their placement in the bimetallic strip?