Which of the following pairs is correctly matched? 1. Electroscope : Device to detect charged bodies 2. Seismograph : Device to measure ocean depth 3. Richter Scale : Scale to measure earthquake magnitude 4. Lightning Conductor : Device to generate electricity Select the correct answer using the code given below:

The correct option is 1 and 3 only . Explanation Scientific instruments are designed to detect, measure, or protect against specific physical phenomena such as electric charge, seismic activity, or atmospheric discharges. - Pair 1 is correctly matched: An Electroscope is a scientific instrument used to detect the presence of electric charge on a body. It operates on the principle of electrostatic repulsion, where leaves (usually gold) diverge when charged. - Pair 2 is incorrectly matched: A Seismograph is an instrument used to detect and record ground motion caused by earthquakes (seismic waves). The instrument used to measure ocean depth is typically a Fathometer or Sonar (Sound Navigation and Ranging). - Pair 3 is correctly matched: The Richter Scale is a quantitative scale used to measure the magnitude (energy released) of an earthquake. - Pair 4 is incorrectly matched: A Lightning Conductor is a metal rod mounted on a building to protect it from lightning strikes. It provides a low-resistance path for the electric discharge to flow safely into the ground. It does not generate electricity. Key Takeaway: An electroscope detects static electric charge, whereas a lightning conductor grounds atmospheric discharge to protect structures. Seismographs record seismic waves, while the Richter scale quantifies their magnitude.

NCERT Class 8 Science — Chapter 3: Some natural phenomena

mcqeasy

Which of the following pairs is correctly matched?

Electroscope : Device to detect charged bodies
Seismograph : Device to measure ocean depth
Richter Scale : Scale to measure earthquake magnitude
Lightning Conductor : Device to generate electricity

Select the correct answer using the code given below:

Official previous-year question

Verified 1 Aug 2026.

Options

A1, 2, 3 and 4
B1, 3 and 4 only
C1 and 3 only
D2 and 4 only

Did you get this right?

Solution

The correct option is

1 and 3 only

Explanation

Scientific instruments are designed to detect, measure, or protect against specific physical phenomena such as electric charge, seismic activity, or atmospheric discharges.

Pair 1 is correctly matched: An Electroscope is a scientific instrument used to detect the presence of electric charge on a body. It operates on the principle of electrostatic repulsion, where leaves (usually gold) diverge when charged.
Pair 2 is incorrectly matched: A Seismograph is an instrument used to detect and record ground motion caused by earthquakes (seismic waves). The instrument used to measure ocean depth is typically a Fathometer or Sonar (Sound Navigation and Ranging).
Pair 3 is correctly matched: The Richter Scale is a quantitative scale used to measure the magnitude (energy released) of an earthquake.
Pair 4 is incorrectly matched: A Lightning Conductor is a metal rod mounted on a building to protect it from lightning strikes. It provides a low-resistance path for the electric discharge to flow safely into the ground. It does not generate electricity.

Key Takeaway: An electroscope detects static electric charge, whereas a lightning conductor grounds atmospheric discharge to protect structures. Seismographs record seismic waves, while the Richter scale quantifies their magnitude.

Your note

More from Chapter 3: Some natural phenomena

With reference to the history of understanding electrical charges, consider the following statements: 1. The ancient Greeks knew that amber attracts light objects like hair when rubbed with fur. 2. Benjamin Franklin proved that lightning and sparks from clothes are two completely different phenomena. 3. The realization of the similarity between lightning and sparks from clothes took approximately two thousand years to occur. Which of the statements given above is/are correct?

medium

Consider the following statements regarding the charging of objects by rubbing: 1. A plastic refill does not acquire any electric charge when rubbed with polythene. 2. When a plastic comb is rubbed with dry hair, both the comb and the hair get charged. 3. The electrical charges generated by rubbing are static in nature. Which of the statements given above is/are correct?

medium

With reference to the interaction between charged objects, consider the following statements: 1. A charged balloon repels another charged balloon. 2. A charged refill repels a charged balloon. 3. A charged refill attracts another charged refill. Which of the statements given above are correct?

easy

By convention, what is the nature of the electric charge acquired by a glass rod when it is rubbed with silk?

easy

Consider the following statements regarding the nature of electric charges: 1. Charges of the same kind repel each other. 2. Charges of different kinds repel each other. 3. A charged glass rod attracts a charged plastic straw rubbed with polythene. Which of the statements given above is/are correct?

medium

Keep practising Chapter 3: Some natural phenomena

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The correct option is

1 and 3 only

Explanation

Scientific instruments are designed to detect, measure, or protect against specific physical phenomena such as electric charge, seismic activity, or atmospheric discharges.

Pair 1 is correctly matched: An Electroscope is a scientific instrument used to detect the presence of electric charge on a body. It operates on the principle of electrostatic repulsion, where leaves (usually gold) diverge when charged.
Pair 2 is incorrectly matched: A Seismograph is an instrument used to detect and record ground motion caused by earthquakes (seismic waves). The instrument used to measure ocean depth is typically a Fathometer or Sonar (Sound Navigation and Ranging).
Pair 3 is correctly matched: The Richter Scale is a quantitative scale used to measure the magnitude (energy released) of an earthquake.
Pair 4 is incorrectly matched: A Lightning Conductor is a metal rod mounted on a building to protect it from lightning strikes. It provides a low-resistance path for the electric discharge to flow safely into the ground. It does not generate electricity.