Chapter 12: Magnetic Effects of Electric Current — Online MCQ Test
SCIENCE · Grade 10 · CBSE(NCERT)
Practice Chapter 12: Magnetic Effects of Electric Current with a free chapter-wise online MCQ test.
This chapter covers: Magnetic field Magnetic field lines Electromagnet Electric motor Electric generator Fleming left hand rule Fleming right hand rule Solenoid Electromagnetic induction.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 12: Magnetic Effects of Electric Current — Important Questions & Answers
What is the SI unit of magnetic field?
- A. Tesla
- B. Weber
- C. Ampere
- D. Ohm
Answer: A. Tesla
The SI unit of magnetic field is tesla, represented by T.
The SI unit of magnetic field is tesla, represented by T.
Outside a bar magnet, magnetic field lines are directed from:
- A. South pole to North pole
- B. North pole to South pole
- C. Centre to both poles
- D. Both poles to the centre
Answer: B. North pole to South pole
Outside a bar magnet, magnetic field lines emerge from the North pole and enter the South pole.
Outside a bar magnet, magnetic field lines emerge from the North pole and enter the South pole.
The deflection of a compass needle near a current-carrying wire shows that:
- A. Current produces heat only
- B. Current produces a magnetic field
- C. Current produces light
- D. The wire becomes electrically neutral
Answer: B. Current produces a magnetic field
A compass needle is deflected due to the magnetic field produced around a current-carrying conductor.
A compass needle is deflected due to the magnetic field produced around a current-carrying conductor.
A solenoid carrying current behaves like a:
- A. Resistor
- B. Bar magnet
- C. Fuse
- D. Switch
Answer: B. Bar magnet
A current-carrying solenoid produces a magnetic field similar to that of a bar magnet.
A current-carrying solenoid produces a magnetic field similar to that of a bar magnet.
A circular loop lies in the plane of the page and the current appears clockwise when viewed by the reader. What is the direction of the magnetic field at the centre of the loop?
- A. Out of the page
- B. Towards the right
- C. Into the page
- D. Towards the left
Answer: C. Into the page
Using the right-hand thumb rule, a clockwise current produces a magnetic field into the page at the centre.
Using the right-hand thumb rule, a clockwise current produces a magnetic field into the page at the centre.
Which change will increase the strength of the magnetic field inside a solenoid?
- A. Decreasing the current through the solenoid
- B. Reducing the number of turns in the solenoid
- C. Increasing the current through the solenoid
- D. Replacing the core with wood
Answer: C. Increasing the current through the solenoid
The magnetic field inside a solenoid increases when the current through it increases.
The magnetic field inside a solenoid increases when the current through it increases.
Which statement correctly describes a uniform magnetic field?
- A. Field lines are curved and crowded at one end only
- B. Field lines are parallel and equally spaced
- C. Field lines intersect at regular intervals
- D. Field lines form random closed loops
Answer: B. Field lines are parallel and equally spaced
A uniform magnetic field is represented by straight, parallel, equally spaced field lines.
A uniform magnetic field is represented by straight, parallel, equally spaced field lines.
Two identical circular loops carry equal currents in opposite directions. What is the net magnetic field at their common centre?
- A. Double the field due to one loop
- B. Zero
- C. Half the field due to one loop
- D. Four times the field due to one loop
Answer: B. Zero
The two loops produce equal magnetic fields in opposite directions at the centre, so they cancel each other.
The two loops produce equal magnetic fields in opposite directions at the centre, so they cancel each other.
In a rectangular coil ABCD of a simple electric motor, sides AB and CD are perpendicular to the magnetic field while BC and DA are parallel to it. Which sides experience the main forces responsible for rotation?
- A. Only BC and DA
- B. Only AB and CD
- C. All four sides equally in the same direction
- D. No side experiences any force
Answer: B. Only AB and CD
The sides perpendicular to the magnetic field experience equal and opposite forces, forming a couple that rotates the coil.
The sides perpendicular to the magnetic field experience equal and opposite forces, forming a couple that rotates the coil.
A straight conductor connected to a galvanometer is placed in a vertically downward magnetic field. In which motion will no induced current be produced?
- A. Moving the conductor towards east
- B. Moving the conductor towards north
- C. Moving the conductor vertically downward
- D. Moving the conductor horizontally across the field
Answer: C. Moving the conductor vertically downward
No induced current is produced when the conductor moves parallel to the magnetic field lines, as it does not cut the field lines.
No induced current is produced when the conductor moves parallel to the magnetic field lines, as it does not cut the field lines.