Question 1

Which of the following represents the symbol for a battery in a circuit diagram?

Accepted Answer

A battery is a combination of two or more cells. In a circuit diagram, it is represented by longer lines representing the positive terminal and thicker, shorter lines representing the negative terminal.

Question 2

When the switch is in the 'ON' position, the electric circuit is:

Accepted Answer

When a switch is in the 'ON' position, the circuit from the positive terminal of the battery to the negative terminal is complete, allowing electric current to flow through it.

Question 3

The safety device used in electrical appliances to prevent damage due to excessive current is called:

Accepted Answer

An electric fuse is a safety device containing a wire made of a special material that melts quickly and breaks when large electric currents pass through it, thus preventing damage.

Question 4

Which effect of electric current is responsible for the working of an electric bell?

Accepted Answer

An electric bell contains an electromagnet. When electric current passes through the coil, it acts like a magnet and attracts the iron strip, producing sound, which is the magnetic effect of current.

Question 5

Which of the following appliances works on the heating effect of electric current?

Accepted Answer

Appliances like electric iron, room heater, and immersion heater work on the heating effect of electric current, where the wire becomes hot and glows when current passes through it.

Electric Current and its Effects — CBSE Class 7 Science Important Questions & Revision Notes