Mark ‘T’ if the statement is true and ‘F’ if it is false:
$(a)$. To make a battery of two cells, the negative terminal of one cell is
connected to the negative terminal of the other cell. $(T/F)$
$(b)$. When the electric current through the fuse exceeds a certain limit, the fuse wire melts and breaks. $(T/F)$
$(c)$. An electromagnet does not attract a piece of iron. $(T/F)$
$(d)$. An electric bell has an electromagnet. $(T/F)$

AcademicPhysicsNCERTClass 7

$(a)$. To make a battery of two cells, the negative terminal of one cell is connected to the negative terminal of the other cell.    (False)

Explanation

In order to make a battery of two cells, the negative terminal of one cell is connected to the positive terminal of the other cell. 

$(b)$. When the electric current through the fuse exceeds a certain limit, the fuse wire melts and breaks.   (True) 


Explanation

A fuse wire is a short-length wire of a low melting point. So if a large current exceeds a safe value (due to short-circuiting or overloading) it heats the fuse wire too much and the wire melts and breaks the circuit.

$(c)$. An electromagnet does not attract a piece of iron.      (False) 

Explanation

An electromagnet is a temporary magnet that works when the current is passed through it. Therefore, it can attract a piece of iron.

$(d)$. An electric bell has an electromagnet.     (True)

Explanation

An electric bell works on the principle of electromagnetism. In an electric bell, a coil of an insulated wire is wrapped around a piece of iron, and when the current passes through the coil it behaves as an electromagnet.

raja
Updated on 10-Oct-2022 13:26:27

Advertisements