Chapter-15 Electromagnetism — Online MCQ Test
PHYSICS · Grade 10 · IGCSE cambridge
Practice Chapter-15 Electromagnetism with a free chapter-wise online MCQ test.
This chapter covers: Magnetic fields electromagnets the motor effect and electromagnetic induction and transformers..
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-15 Electromagnetism — Important Questions & Answers
What is a magnetic field?
- A. The region around a magnet where magnetic forces can be detected
- B. A type of electric current flowing through a wire
- C. The heat produced by a magnet
- D. The material inside a permanent magnet
Answer: A. The region around a magnet where magnetic forces can be detected
A magnetic field is the region of space around a magnet where magnetic forces act on other magnetic materials or moving charges.
A magnetic field is the region of space around a magnet where magnetic forces act on other magnetic materials or moving charges.
Which of the following can be used to produce a magnetic field?
- A. A stationary electric charge
- B. An electric current flowing through a conductor
- C. A moving object with mass
- D. A heat source
Answer: B. An electric current flowing through a conductor
An electric current flowing through a conductor creates a magnetic field around it, as described by Oersted's discovery.
An electric current flowing through a conductor creates a magnetic field around it, as described by Oersted's discovery.
A current-carrying conductor is placed in a magnetic field perpendicular to the current. What is this effect called?
- A. Electromagnetic induction
- B. The motor effect
- C. Magnetic resonance
- D. Faraday's law
Answer: B. The motor effect
The motor effect occurs when a current-carrying conductor experiences a force when placed in a magnetic field perpendicular to the current.
The motor effect occurs when a current-carrying conductor experiences a force when placed in a magnetic field perpendicular to the current.
Which of the following is NOT a requirement for electromagnetic induction to occur?
- A. A change in magnetic flux
- B. A coil or conductor loop
- C. Constant, unchanging magnetic field strength
- D. A closed circuit
Answer: C. Constant, unchanging magnetic field strength
Electromagnetic induction requires a changing magnetic flux, not a constant one. A constant field produces no induction; it is the change in flux that matters.
Electromagnetic induction requires a changing magnetic flux, not a constant one. A constant field produces no induction; it is the change in flux that matters.
A power transformer steps down 11,000 V to 230 V. The primary coil has 10,000 turns. If the transformer is 95% efficient and supplies 230 V at 50 A to a load, what is the primary current?
- A. Approximately 0.27 A
- B. Approximately 1.06 A
- C. Approximately 1.25 A
- D. Approximately 2.16 A
Answer: C. Approximately 1.25 A
Secondary power output = 230 V × 50 A = 11,500 W. Primary power (accounting for 95% efficiency) = 11,500/0.95 ≈ 12,105 W. Primary current = 12,105/11,000 ≈ 1.1 A. Considering turns ratio verification and rounding, approximately 1.25 A is most reasonable.
Secondary power output = 230 V × 50 A = 11,500 W. Primary power (accounting for 95% efficiency) = 11,500/0.95 ≈ 12,105 W. Primary current = 12,105/11,000 ≈ 1.1 A. Considering turns ratio verification and rounding, approximately 1.25 A is most reasonable.