Question

The direction of the induced e.m.f. is determined by:
A. Fleming’s left hand rule
B. Fleming’s right hand rule
C. Maxwell’s right hand screw rule
D. Ampere’s rule of swimming

Answer 1

Hint: An EMF or Electromotive force is defined as the electric potential produced by changing the magnetic field in the system. On the other hand, an induced EMF is defined as the EMF induced by the dynamic interaction of the conductor with the magnetic field.

Complete answer:
Now, consider a conductor like a wire which is attached to a circuit. When the conductor moves in the magnetic field then the electric current will be induced in the conductor. This induced current will give rise to induced e.m.f. that tells us that the flow of current is from positive to negative charge. Therefore, we will use Fleming’s right-hand thumb rule. Now, we will discuss Fleming’s right-hand thumb rule.

In Fleming’s right-hand thumb rule, we will hold the right hand in which thumb, index finger, and middle finger are aligned perpendicular to each other. Here, the thumb will represent the direction of motion of the conductor, the index finger will represent the direction of the magnetic field and the middle finger will represent the direction of the current in the conductor. The direction of the current will provide the direction of the induced e.m.f.
Therefore, the direction of the induced e.m.f. is determined by Fleming’s right-hand thumb rule.

Hence, option B is the correct option.

Note:Here, Fleming’s left-hand rule is used to determine the direction of the force acting on the conductor. Maxwell’s right-hand screw rule is used to determine the direction of the magnetic field. On the other hand, Ampere’s rule of swimming tells that if a person is swimming in the pool, then the head of the person will be directed towards the magnetic needle.