What is electromotive force?
PhysicsClass 10CBSEAnswered 28 May 2026
Answer
EMF (ε) is the total energy supplied by a source per unit charge as it drives charge around a complete circuit.
- Unit: Volt (V) not a force, it is energy per charge.
- EMF = maximum terminal voltage when no current flows (open circuit).
EMF vs. Terminal Voltage: Terminal Voltage = EMF − I × r (internal resistance)
Sources of EMF: Batteries, generators, solar cells, thermocouples.
EMF is the total energy provided per coulomb of charge by an electrical source, representing its maximum ability to drive current.
Suggested Q&A
Physics · Class 10- PhysicsClass 10Where does the sun rise and set?
- PhysicsClass 10What is Zener voltage?
- PhysicsClass 10What is magnetic induction?
- PhysicsClass 10What is electromagnetic induction?
- PhysicsClass 10What are eddy currents? Write two applications.
- PhysicsClass 10How do you calculate current through a 6-ohm resistor using Ohm's law?