Question

If a coil carrying current is placed in a uniform magnetic field, then

• A. emf is produced
• B. Torque is produced
• C. Force is produced
• D. Torque and force is produced

Hint:

A current-carrying coil placed in a magnetic field experiences torque, which causes it to rotate. This principle is used in electric motors.

Answer 1

The Correct Option is B

Step 1: Understanding the Behavior of a Coil in a Magnetic Field
When a coil carrying a current is placed in a uniform magnetic field, it experiences a torque due to the interaction between the magnetic field and the current in the coil.
The torque tends to rotate the coil to align it with the magnetic field.
Step 2: Why Other Options are Incorrect
Option (a) is incorrect because an emf is not produced simply by placing the coil in a uniform magnetic field.
An emf is generated when there is relative motion between the coil and the magnetic field or if the field changes with time.

Option (c) is incorrect because no net force is produced on the coil in a uniform magnetic field.
The force acting on opposite sides of the coil cancels out, leaving only torque.

Option (d) is incorrect because while torque is produced, there is no net force in a uniform magnetic field.
Step 3: Conclusion
Thus, the correct answer is that torque is produced when a current-carrying coil is placed in a uniform magnetic field.