Practise 24 real Federal Board questions on Electromagnetism from 2023 to 2026. See the answer and explanation as soon as you answer.
Electromagnetism is one of the 16 main chapters in our Federal Board Matric Physics question bank (10th class), and about 6% of its real questions come from it. Tayyari Karo has 24 real questions on this chapter from 2023 to 2026; 8 are multiple choice and marked instantly, and the rest are short and long questions with a model answer. By difficulty: 12 easy, 12 medium.
Work through the questions below, then open the explanation for each one. Redo the ones you missed a few days later.
These are real past-paper questions. Think of your answer first, then open the explanation.
If the direction of current in a conductor is reversed, the direction of force on it will:
Answer: A. Reverse
F = IL × B — reversing I reverses the force (Fleming's left‑hand rule).
Which instrument converts electrical energy into mechanical energy?
Answer: B. Electric motor
A motor converts electrical energy into rotation; a generator does the reverse.
If a DC source of 80 V is connected to the primary coil of a transformer with Np = 20 turns, Ns = 5 turns then Vs =
Answer: B. Zero
A transformer works only with a changing (AC) current. A steady DC produces no changing flux, so no e.m.f. is induced: Vs = 0.
What principle is used in the working of a transformer?
Answer: A. Mutual induction
A changing current in the primary induces an e.m.f. in the secondary — mutual induction.
If Ip = 100 Is, the turn ratio (Ns : Np) of the transformer is:
Answer: A. 100 : 1
Ns/Np = Ip/Is = 100, so Ns : Np = 100 : 1 — a step‑up transformer (Np : Ns = 1 : 100).
Which device converts mechanical energy into electrical energy?
Answer: D. Generator
A generator converts mechanical energy into electrical energy; a motor does the opposite.
State Lenz's law. How does it determine the direction of induced current? Explain briefly.
Lenz's law: the direction of an induced current is such that it opposes the change (in magnetic flux) which produces it.
Application: when the N‑pole of a magnet is pushed towards a coil, the induced current flows so that the near face of the coil becomes a north pole (opposing the approach — repulsion). When the magnet is withdrawn, the current reverses so that the near face becomes a south pole (opposing the withdrawal — attraction). Knowing the polarity, the right‑hand rule gives the current direction. The law follows from conservation of energy.
Explain the construction and working of a D.C. motor. Also make a well‑labelled sketch.
A DC motor converts electrical energy into mechanical (rotational) energy. It works on the principle that a current‑carrying conductor placed in a magnetic field experiences a force (F = BIL).
Construction (sketch): (1) a rectangular coil (armature) of many turns of insulated wire wound on a soft‑iron core, mounted on an axle so it can rotate; (2) a strong magnetic field from permanent magnets or field electromagnets with curved pole pieces (N and S); (3) a split‑ring commutator — two half‑rings of copper fixed to the axle, each connected to one end of the coil; (4) two carbon brushes pressing on the commutator, connected to the DC supply. …
The full model answer is in the app.
| Session | Questions |
|---|---|
| 2026 Annual | 4 |
| 2025 1st Annual | 6 |
| 2025 2nd Annual | 3 |
| 2024 Annual | 6 |
| 2023 Annual | 5 |
24 real Federal Board (FBISE) Physics questions on Electromagnetism from 2023 to 2026, for 10th class. Each one shows the session it came from.
No. We could not find an official FBISE marking scheme for these papers, so the answers and explanations are written by Tayyari Karo for practice. Check anything important with your teacher or textbook.
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