SSC CGL 2025 Tier-I · 16 September 2025, Shift 1 · General Awareness · Question 17 of 100

We transcribed this text from the pictures on a candidate's response sheet for this shift; the answer is the key SSC colour-marked on that sheet. Solution last reviewed 13 September 2026.

Where this paper and its answers come from

SSC does not publish CGL question papers or a public answer key. From 2025 the candidate response sheet prints every question and option as a picture, so the text here is transcribed from those pictures for this shift and checked against them independently; where the layout carries meaning, the picture is shown as well. Each answer is the key SSC colour-marked on that sheet. SSC released a tentative key for challenge and later its final one, both only to candidates behind a login, and the sheet does not say which of the two it carries. The solutions are written by UnlockIAS.

Which of the following pairs is correctly matched regarding electromagnetic devices?

(a)Electric Generator : Converts electrical energy to mechanical energy.
(b)Transformer : Operates on DC current to change voltage.
(c)Electromagnet : A permanent magnet.
(d)Electric Bell : Uses the magnetic effect of electric current.

Answer

Why

Correct — D. An electric bell works on an electromagnet. Current in the coil magnetises it, it pulls an iron strip, and the hammer on the strip strikes the gong.

The pull breaks the circuit, the coil stops being a magnet and the strip springs back. Contact is remade and the cycle repeats → option (d).

Why the others are wrong

(a)
Electric Generator : Converts electrical energy to mechanical energy. — An electric generator converts mechanical energy into electrical energy. The reverse, electrical to mechanical, is what an electric motor does.
(b)
Transformer : Operates on DC current to change voltage. — A transformer needs alternating current. Only a changing current in one coil induces a voltage in the other, so a steady DC gives no induced voltage.
(c)
Electromagnet : A permanent magnet. — An electromagnet is a temporary magnet. It is magnetic only while current flows, which is exactly what lets a bell's circuit switch on and off.

Concept

All four devices link electricity and magnetism, in one of two directions.

Current makes magnetism: a coil carrying current becomes a magnet. The electromagnet, the electric bell and the motor use this.

Changing magnetism makes current: electromagnetic induction, discovered by Faraday in 1831. The generator and the transformer use this.

Each wrong pair is a reversal: generator for motor, DC for AC, permanent for temporary. Check the direction of the energy change before the device name.

Key facts

Electric motor: electrical energy → mechanical energy.
Electric generator: mechanical energy → electrical energy, by electromagnetic induction.
A transformer works on alternating current, by mutual induction between two coils.
An electromagnet is a temporary magnet: magnetic only while current flows.

Study next

Fleming's left-hand rule (motor) and right-hand rule (generator)Step-up and step-down transformersUses of electromagnets: bells, cranes, relays

Common traps

Swapping motor and generator — ask which energy goes in and which comes out.
Accepting a DC transformer because transformers change voltage — they need a changing current to do it.

Electromagnetic induction, the principle behind the generator and the transformer, is asked through Faraday's 1831 experiment at 23 Sep 2024, 16:00, GA Q.5.

Related PYQs

No directly related past PYQ was found.

Topic: Scientific Research — all 220 SSC CGL questions on it, every solved shift.