Q: What is the missing label at \$\star\$ ?

The element marked \$\star\$ is called the contact screw.Contact screw completes the circuit in an electric bell. When the iron strip is in contact with the screw , the current flows through the coil and it becomes an electromagnet. The hammer at one end of iron strip strikes the gong and bell is rung.

Question 1

Which among the following pair of elements are suitable in the construction of electric bell?

Accepted Answer

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Question 2

The electric bell consists of a _______ wound on an _______.

Accepted Answer

An electric bell has a coil of wire wound around a piece of iron which acts like an electromagnet. An iron strip with a hammer is kept close to the electromagnet. There is a contact screw near the iron strip. When the iron strip is in contact with the screw, current flows through the coil and becomes an electromagnet.

Question 3

What will be the order in which the bulbs $A,\ B,$ and $C$ will glow when the switch is moved to the 'on' position?

Accepted Answer

When the switch is moved to the on position, the circuit is closed. All the bulbs will glow together.

Question 4

What is kept close to the electromagnet in the electric bell?

Accepted Answer

An iron strip (armature) with a hammer at one end is kept close to the electromagnet in an electric bell, thus option $C$ is correct

Question 5

Which of the following acts an electromagnet in an electric bell?

Accepted Answer

The electric bell consists of a coil of wire wound on an iron piece. When the current flow through the coil, it acts as a magnet. Magnetic property in the coil develop due to current flow so this magnet is known as electromagnet. thus option $B$ is correct.

Question 6

The diagram shows the circuit of an door bell. What happens when the bell button is switched on then switched off?

Switch on Swithc off
(A) $1$ ting is heard Silence
(B) $1$ ting is heard $1$ ting is heard
(C) Continuous Silence
(D) Silence Continuous ringing

Accepted Answer

In the given bell circuit, when we press the bell button (switched on), current will flow through the circuit and the solenoid will become magnetised. It will produce magnetic field that will attract the soft iron which will hit the gong 1. So a ting will be heard.After switching off, the solenoid will become demagnetised and will not produce magnetic field. The soft iron won't be attracted. The hammer will come back to its mean position due to the pull of the spring metal strip. The other (right) face of the hammer will hit the gong 2. So another ting is heard.

Question 7

What is the missing label at $\star$ ?

Accepted Answer

The element marked $\star$ is called the contact screw.Contact screw completes the circuit in an electric bell. When the iron strip is in contact with the screw , the current flows through the coil and it becomes an electromagnet. The hammer at one end of iron strip strikes the gong and bell is rung.

Question 8

Symbol of switch in 'ON' position is -

Accepted Answer

Third option is the symbol of 'on' switch.Answer-(C)

Question 9

Identify the circuit (Figure 12.3) in which the electrical components have been properly connected

Accepted Answer

Hint: Check the connections of the Voltmeter and Ammeter.Step 1: Checking if the Voltmeter is connected in parallel and Ammeter is connected in series.   In circuits $(i)$ and $(iii)$, Voltmeter is connected in series. In circuit $(iii)$ the ammeter is connected in parallel. In circuits $(i)$ and $(iii)$, connections are not proper. In circuits $(ii)$ and $(iv)$, the Voltmeter and Ammeter are connected in parallel and series respectively. Step 2: Checking if the terminals are connected properly.   In circuit $(iv)$, the positive terminal of the ammeter is connected with the negative terminal of the cell. Hence it is not proper. Whereas in circuit $(ii)$, all the terminals are properly connected. Therefore option $(B)$ is the correct option.

Question 10

Would any of the bulbs glow when the switch is in the 'off' position?

Accepted Answer

When the switch is in the 'off'. position, no bulb will glow as the circuit is incomplete and no current flows through the circuit.Also these bulbs are in series which means that if current through one lamp is zero , current through every lamp will be zero and no bulb will light up.Correct option is (D).

Electric Current And Its Effects

Physics
2242 Views

Which among the following pair of elements are suitable in the construction of electric bell?

The electric bell consists of a _ wound on an _.

What will be the order in which the bulbs $A, B,$ and $C$ will glow when the switch is moved to the 'on' position?

What is kept close to the electromagnet in the electric bell?

Which of the following acts an electromagnet in an electric bell?

The diagram shows the circuit of an door bell. What happens when the bell button is switched on then switched off?

Switch on Swithc off
(A) $1$ ting is heard Silence
(B) $1$ ting is heard $1$ ting is heard
(C) Continuous Silence
(D) Silence Continuous ringing

What is the missing label at $⋆$ ?

Symbol of switch in 'ON' position is -

Identify the circuit (Figure 12.3) in which the electrical components have been properly connected

Would any of the bulbs glow when the switch is in the 'off' position?

	Switch on	Swithc off
(A)	$1$ ting is heard	Silence
(B)	$1$ ting is heard	$1$ ting is heard
(C)	Continuous	Silence
(D)	Silence	Continuous ringing

Electric Current And Its Effects

Physics 2242 Views

Which among the following pair of elements are suitable in the construction of electric bell?

The electric bell consists of a _______ wound on an _______.

What will be the order in which the bulbs A, B, and C will glow when the switch is moved to the 'on' position?

What is kept close to the electromagnet in the electric bell?

Which of the following acts an electromagnet in an electric bell?

The diagram shows the circuit of an door bell. What happens when the bell button is switched on then switched off? Switch onSwithc off(A)1 ting is heardSilence(B)1 ting is heard1 ting is heard(C)ContinuousSilence(D)SilenceContinuous ringing

What is the missing label at ⋆ ?

Symbol of switch in 'ON' position is -

Identify the circuit (Figure 12.3) in which the electrical components have been properly connected

Would any of the bulbs glow when the switch is in the 'off' position?

Physics
2242 Views

The electric bell consists of a _ wound on an _.

What will be the order in which the bulbs $A, B,$ and $C$ will glow when the switch is moved to the 'on' position?

The diagram shows the circuit of an door bell. What happens when the bell button is switched on then switched off?

Switch on Swithc off
(A) $1$ ting is heard Silence
(B) $1$ ting is heard $1$ ting is heard
(C) Continuous Silence
(D) Silence Continuous ringing

What is the missing label at $⋆$ ?