Electric Current and Its Effects Quiz

In a parallel circuit with three identical bulbs, what happens to the brightness of the remaining bulbs if one bulb is removed?

1. The remaining bulbs glow dimmer
2. Brightness increases
3. They go off
4. Brightness remains unchanged

Answer: (d) Brightness remains unchanged

Read the following statements and choose the correct option. Statements: 1. When electric current flows through a wire, it creates a magnetic field around it. 2. The magnetic field becomes stronger if the wire is coiled. 3. The magnetic field does not change even if the direction of current is reversed.

1. 1 and 2 are correct
2. 2 and 3 are correct
3. Only 1 is correct
4. only 3 is correct

Answer: (a) 1 and 2 are correct

In a circuit, where should a voltmeter be connected to measure the potential difference across a resistor?

1. In series with the resistor
2. In parallel across the resistor
3. In series with the power supply
4. In parallel with the switch

Answer: (b) In parallel across the resistor

Read the following statements carefully and choose the correct option: Assertion (A): When additional bulbs are connected in series, the brightness of each bulb decreases. Reason (R): Adding more bulbs in series increases the total resistance of the circuit.

1. A and R are true, and R is the correct explanation of A
2. A and R are true, but R is not the correct explanation of A
3. A is true, but R is false
4. A is false, but R is true

Answer: (a) A and R are true, and R is the correct explanation of A

You are designing a simple circuit using the four components shown (A–D). The circuit must meet the following conditions: 1. It should only allow current to flow when manually controlled. 2. It must produce visible output when functioning. 3. The path must be complete and low-resistance to avoid unnecessary energy loss. 4. The power supply must be correctly oriented. Which one of the following sequences (of symbols A–D) represents the correct order and correct function of all components when constructing such a circuit on paper?

1. D → B → A → C
2. C → D → B → A
3. C → A → D → B
4. C → D → A → B

Answer: (d) C → D → A → B

Based on this diagram, which of the following statements is most accurate?

1. X acts as the cathode and collects electrons from the external circuit
2. X acts as the anode and is the source of electrons
3. Y acts as the electrolyte and conducts ions within the paste
4. Y is the positive terminal, and X is the negative terminal of the dry cell.

Answer: (a) X acts as the cathode and collects electrons from the external circuit

The diagram shows the internal structure of a filament bulb with five labelled parts. Consider the following combinations of labelled parts with their materials and functions: A) Part 1 – Tungsten – High melting point filament that emits light when heated B) Part 2 – Glass – Provides insulation and maintains vacuum or inert gas environment C) Part 3 – Aluminium – Insulated contact to prevent electrical conduction to the casing D) Part 5 – Copper – Support wire that also acts as an electrical lead-in Which of the above combinations is fully correct?

1. A and B only
2. A, B, and D only
3. A, B, C, and D
4. A, C, and D only

Answer: (b) A, B, and D only

In the four circuits, all the bulbs and batteries are new and identical. Which of the following two bulbs have the same brightness?

1. A and D
2. B and C
3. B and D
4. C and D

Answer: (b) B and C

What would happen if an extra bulb is added to Circuit A?

1. All bulbs glow brighter
2. Brightness of all bulbs increases
3. Brightness of all bulbs decreases
4. The current in each bulb increases

Answer: (c) Brightness of all bulbs decreases

Consider the following statements: 1. The electromagnet is the only component in an electric bell that uses magnetic force. 2. The armature and hammer are designed to move freely in response to magnetic fields. Which of the statements is/are correct?

1. Only 1
2. Only 2
3. Both 1 and 2
4. Neither 1 nor 2

Answer: (c) Both 1 and 2