Join 60,000+ competitive exam aspirants
or with email
Your Cart
Subtotal₹0
Total₹0
Examoogle • User • info@examoogle.com • EE-2024-8821
Chapter 1 of 12 • Page 1 of 248🔒 Protected PDF • Watermarked
Join 60,000+ competitive exam aspirants
Fleming’s Left-Hand Rule is used to determine _________.
the amount of current flowing through the conductor
the strength of the magnetic field
the direction of force on a current-carrying conductor
the magnitude of the force on a current-carrying conductor
the direction of force on a current-carrying conductor
Fleming's Left-Hand Rule is a visual heuristic used to determine the direction of the force acting on a current-carrying conductor placed in an external magnetic field. It specifically identifies the vector direction of the Lorentz force experienced by the charges moving through the conductor.
Fleming's Left-Hand Rule is a visual heuristic used to determine the direction of the force acting on a current-carrying conductor placed in an external magnetic field. It specifically identifies the vector direction of the Lorentz force experienced by the charges moving through the conductor.
Think of it like pushing a door; if the magnetic field is the orientation of the hinge and the current is the direction you push, the thumb indicates which way the door swings open.
FBI rule: F (Thumb - Force), B (Forefinger - Magnetic Field), I (Middle finger - Current).
F=I(L×B)
F=BIlsinθ — where F is the force, B is magnetic field strength, I is current, and l is conductor length.
When a current I flows through a conductor of length L placed in a magnetic field B, a Lorentz force F is exerted on it. According to the rule, if the thumb, forefinger, and middle finger of the left hand are held mutually perpendicular, the forefinger points in the direction of the magnetic field, the middle finger points in the direction of the current, and the thumb indicates the direction of the force.
The fingers must be held at 90° to each other for the rule to apply.
The rule is specifically designed for electric motors.
It demonstrates the interaction between electricity and magnetism.
Simple, intuitive, and requires no complex mathematical calculations to find direction.
Provides only direction, not the magnitude of the force.
Designing electric motors
Understanding the motion of speakers and galvanometers
| Feature | Fleming's Left-Hand Rule | Fleming's Right-Hand Rule |
|---|---|---|
Hand Used | Left-Hand | Right-Hand |
Application | Electric Motors | Electric Generators |
The magnitude of the force is calculated using the formula F=BIlsinθ, which confirms that force is zero if the current is parallel to the magnetic field (θ=0°).
Option A and B are incorrect because the rule identifies direction, not the scalar value of current or field strength.
C is correct — Fleming’s Left-Hand Rule is specifically used to determine the direction of the force acting on a current-carrying conductor in a magnetic field.
Always remember: Left-Hand for Motors (current creates motion) and Right-Hand for Generators (motion creates current).
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download • 100K+ Aspirants