Question

________ is the rule used to know the direction of the induced current in the circuit.

• A. Fleming's left hand rule
• B. Fleming's right hand rule
• C. Right hand thumb rule
• D. Ampere's rule

Hint:

Fleming's left hand rule is for motors. Fleming's right hand rule is for generators and induced current.

Answer 1

The Correct Option is B

Concept:
When a conductor moves in a magnetic field, an induced current is produced in the conductor. The direction of this induced current is found by Fleming's right hand rule. Fleming's right hand rule is mainly used in the case of generators, where mechanical energy is converted into electrical energy.

Step 1: Understand what is asked.
The question asks for the rule used to find the direction of induced current. Induced current is produced due to electromagnetic induction. So we need the rule related to electromagnetic induction.

Step 2: Recall Fleming's right hand rule.
According to Fleming's right hand rule, stretch the thumb, forefinger and middle finger of the right hand mutually perpendicular to each other. Then: \[ \text{Thumb} \rightarrow \text{direction of motion of conductor} \] \[ \text{Forefinger} \rightarrow \text{direction of magnetic field} \] \[ \text{Middle finger} \rightarrow \text{direction of induced current} \]

Step 3: Differentiate from Fleming's left hand rule.
Fleming's left hand rule is used for motors. It gives the direction of force or motion when current flows through a conductor placed in a magnetic field. But this question asks about induced current, so Fleming's right hand rule is used.

Step 4: Check the options.
Option (A) Fleming's left hand rule is used for motor effect, not induced current.
Option (B) Fleming's right hand rule is used to find direction of induced current.
Option (C) Right hand thumb rule is used to find direction of magnetic field around a current-carrying conductor.
Option (D) Ampere's rule is related to magnetic field and current, not directly for induced current direction in this case. Hence, the correct answer is: \[ \boxed{(B)\ \text{Fleming's right hand rule}} \]