Open and Closed Circuits

Q. A switch is the device which controls the flow of current through a circuit.

1. True
2. False

Q. A switch is a simple device that is used:

1. Either to complete or break a circuit
2. Only to complete the circuit
3. Only to break the circuit
4. Only to fill gaps in the circuit

Q.

Filament of a bulb is

1. a metal case

2. metal tip at the centre of the base

3. two thick wires

4. a thin wire

Q.
Identify the type of circuit given in the diagram.​

1. Open circuit
2. Simple circuit
3. Parallel circuit
4. Series circuit

Q. Choose the correct option:

Statement 1: The following figure represents the conventional flow of current in a circuit.


Statement 2: The actual direction of flow of electrons is opposite to the conventional direction of the flow of current.

1. Both the statements are correct.
2. Statement 1 is correct but statement 2 is incorrect.
3. Statement 1 is incorrect but statement 2 is correct.
4. Both the statements are incorrect.

Q.

Choose the incorrect statement.

1. A switch is the source of electric current in a circuit.

2. A switch helps to complete or break the circuit.

3. A switch helps us to use electricity as per our requirement.

4. When the switch is open there is an air gap between its terminals

Q.

Boojho made the circuit given in Fig. and observed that the bulb did not glow. On Paheli’s suggestion, he added one more cell in the circuit. The bulb now glows. Explain.

Fig. \( 14.3 \)

Q.

Type of circuit where each appliance works independently.

Q.

Write one example of the conversion of electrical energy into light energy.

Q.

In which condition, does a bulb glow when connected to a cell ?

Q. Current flows through an electric circuit when it is open.

1. False
2. True

Q.

A break in the filament of an electric bulb means________.

1. the switch is on

2. the circuit is complete

3. the switch is off

4. the circuit is incomplete

Q.
Which of the following should be placed in box 'X' to make the bulb glow more brightly?

1. Bulb
2. Cell
3. Fuse
4. Switch

Q. Pavani has been failing for a while in making a torch light glow. What could be the problem?

1. The torch light is very new.
2. She might not have inserted the cells in correct order.
3. The bulb of the torch light might have been fused.
4. The cells might have been died out.

Q. What is meant by internal resistance in circuit ?

Q.

While connecting a bulb to a battery, one of the terminals of the battery was left disconnected. Pick the correct statement.

1. Brightness of the bulb would decrease

2. Bulb would fuse

3. Brightness of the bulb would increase

4. Bulb would not glow

Q. An electric bulb in a closed circuit is not glowing. Which of the following can be a reason?

1. Bulb's filament is broken.
2. Filament of the bulb is made of Tungsten.
3. Wires are made of copper.
4. Switch in the circuit is on.

Q.

In a closed circuit, electrons flow from negative to positive terminal of a cell.

1. True

2. False

Q.

Imagine your friend made the following circuit for an experiment, out of curiosity:

If he connects both the wires to a single terminal of the bulb, the bulb starts glowing as soon as the wires are connected to the cell.

1. True

2. False

Q. In a circuit with one bulb, another identical bulb is added in series. Which of the following is observed?

1. They do not glow.
2. The brightness of the individual bulb reduces.
3. The bulbs get fused.
4. The brightness of the individual bulb increases.

Q. If an electric switch is off then:

1. Less current flows through the circuit.
2. Direction of current gets reversed.
3. Excess current flows through the circuit.
4. No current flows through the circuit.