Chapter 10: Electromagnetism — Online MCQ Test
PHYSICAL SCIENCES · CLASS 10th · Telangana State Board
Practice Chapter 10: Electromagnetism with a free chapter-wise online MCQ test.
This chapter covers: Exploring the connection between electricity and magnetism this chapter details Hans Christian Oersted's discovery of magnetic fields around current-carrying conductors. Students l....
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Chapter 10: Electromagnetism — Important Questions & Answers
Who discovered that a current-carrying conductor produces a magnetic field around it?
- A. Hans Christian Oersted
- B. Michael Faraday
- C. John Fleming
- D. James Clerk Maxwell
Answer: A. Hans Christian Oersted
Hans Christian Oersted's discovery in 1820 demonstrated the connection between electricity and magnetism by showing a compass needle deflects near a current-carrying wire.
Hans Christian Oersted's discovery in 1820 demonstrated the connection between electricity and magnetism by showing a compass needle deflects near a current-carrying wire.
What is a solenoid?
- A. A single loop of wire carrying current
- B. A coil of wire wound in tight, successive loops carrying current
- C. A permanent magnet used in motors
- D. A device that measures electric current
Answer: B. A coil of wire wound in tight, successive loops carrying current
A solenoid is a coil of insulated wire wound tightly in successive loops that produces a strong magnetic field when current flows through it.
A solenoid is a coil of insulated wire wound tightly in successive loops that produces a strong magnetic field when current flows through it.
Which of the following statements about Faraday's Law is correct?
- A. A changing magnetic field produces a constant electric field
- B. A changing magnetic flux through a coil induces an electromotive force (EMF)
- C. A static magnetic field always induces current in any conductor
- D. Induced EMF depends only on the number of turns in the coil
Answer: B. A changing magnetic flux through a coil induces an electromotive force (EMF)
Faraday's Law of Electromagnetic Induction states that a change in magnetic flux through a coil induces an EMF, which is the fundamental principle behind generators.
Faraday's Law of Electromagnetic Induction states that a change in magnetic flux through a coil induces an EMF, which is the fundamental principle behind generators.
A solenoid with 500 turns carries current I. If the current is doubled, the magnetic field strength becomes:
- A. Half of the original value
- B. Same as the original value
- C. Double the original value
- D. Four times the original value
Answer: C. Double the original value
Magnetic field in a solenoid is directly proportional to current (B ∝ nI); therefore, doubling the current doubles the magnetic field strength.
Magnetic field in a solenoid is directly proportional to current (B ∝ nI); therefore, doubling the current doubles the magnetic field strength.
Consider a scenario: A copper wire coil is placed near a solenoid carrying AC current. According to Lenz's Law, the induced current in the coil will:
- A. Always flow in the same direction as the solenoid's current
- B. Flow in a direction to oppose the change in magnetic flux from the solenoid
- C. Not flow because copper is not ferromagnetic
- D. Flow only when the solenoid current reaches its maximum value
Answer: B. Flow in a direction to oppose the change in magnetic flux from the solenoid
Lenz's Law states that induced current opposes the change in magnetic flux that caused it; as AC current in the solenoid changes, the induced current in the coil creates a field opposing this change.
Lenz's Law states that induced current opposes the change in magnetic flux that caused it; as AC current in the solenoid changes, the induced current in the coil creates a field opposing this change.