Question 1

In electric heater:

Accepted Answer

When a current passes through an electric heater, it becomes very hot and becomes a source of heat. Therefore, in an electric heater, electrical energy is converted into heat energy.

Question 2

A/an ............... is employed in an electric bell.

Accepted Answer

An electromagnet is employed in an electric bell.When the push button is pressed the electric circuit is completed and the armature is attracted towards the electromagnet. As a result, the small spring gets detached from the screw due to which the electric circuit is broken and the electromagnet is demagnetized. Hence, the attraction disappears and the armature is brought back by the spring to its original position. Contact of the spring with the screw is now remade, which completes the electric circuit. The action is repeated over and over again continuously. The armature vibrates and the hammer attached to it strikes the gong and the bell rings and sound is produced.

Question 3

In an electric bell, a flat ................. spring brings the armature back to its original position.

Accepted Answer

In an electric bell, a flat steel spring brings the armature back to its original position.Working of an electric bell:When the push button is pressed the electric circuit is completed and the armature is attracted towards the electromagnet as a result, the small spring gets detached from the screw due to which the electric circuit is broken and the electromagnet is demagnetized. Hence, the attraction disappears and the armature is brought back by the spring to its original position. Contact of the spring with the screw is now remade, which completes the electric circuit. The action is repeated over and over again consequently. The armature vibrates and the hammer attached to it strikes the gong and the bell rings and sound is produced.

Question 4

When the switch of an electric bell is pushed

Accepted Answer

When the switch of an electric bell is pushed, the circuit is closed and the current starts flowing through the electromagnet in the bell & the bell starts ringing.OPTION : B is correct

Question 5

The longer line in the symbol of a cell denotes

Accepted Answer

The longer vertical line in the symbol of a cell represents the positive terminal and the shorter line in the symbol of a cell represents the negative terminal.

Question 6

The shorter line in the symbol of a electric cell represents:

Accepted Answer

The shorter, thicker vertical line in the symbol of a cell represents the negative terminal.The longer, thinner vertical line in the symbol of a cell represents the positive terminal.

Question 7

A rheostat is used in an electrical circuit

Accepted Answer

A rheostat is a variable resistor which is used to control current. they are able to vary the resistance in circuit without interruption. the construction of a rheostat is very similar to potentiometer .Thus A rheostat is used in circuit to change the resistance of the circuit. so option correct is A.

Question 8

Which of the following is the symbol for a bulb?

Accepted Answer

Option D represent symbol of bulb.

Question 9

Why are the contact points of an electric bell made from silver-cadmium alloy?

Accepted Answer

Contact spring is a flat steel spring, slightly bent and fixed to the armature with the help of screws. The other end of the spring is attached to contact point A, made of silver-cadmium alloy. This alloy does not get oxidised easily due to sparkling.

Question 10

The figure given represents:

Accepted Answer

Correct Option is B.Explanation for the correct answer :The given figure represents the  open circuit. Current do not flows in the circuit, and switch is said to be in OFF position.

Electric Current And Its Effects

Physics
2734 Views

In electric heater:

A/an ............... is employed in an electric bell.

In an electric bell, a flat ................. spring brings the armature back to its original position.

When the switch of an electric bell is pushed

The longer line in the symbol of a cell denotes

The shorter line in the symbol of a electric cell represents:

A rheostat is used in an electrical circuit

Which of the following is the symbol for a bulb?

Why are the contact points of an electric bell made from silver-cadmium alloy?

The figure given represents:

Electric Current And Its Effects

Physics 2734 Views

In electric heater:

A/an ............... is employed in an electric bell.

In an electric bell, a flat ................. spring brings the armature back to its original position.

When the switch of an electric bell is pushed

The longer line in the symbol of a cell denotes

The shorter line in the symbol of a electric cell represents:

A rheostat is used in an electrical circuit

Which of the following is the symbol for a bulb?

Why are the contact points of an electric bell made from silver-cadmium alloy?

The figure given represents:

Physics
2734 Views