In an AC generator, a coil with N turns, all of the same area A and total resistance R, rotates with frequency ω in a magnetic field B. The maximum value of emf generated in the coil is

CONCEPT:

AC Generator

• An AC generator is a device that converts mechanical energy into electrical energy using the principle of electromagnetic induction.
• The emf (electromotive force) generated in a coil rotating in a magnetic field depends on the number of turns in the coil, the area of the coil, the magnetic field strength, and the angular frequency of rotation.

EXPLANATION:

• Let's examine the given options:
  • Option 1: N.A.B.R.ω
    • This option includes resistance (R), which is not part of the formula for the maximum emf generated.
  • Option 2: N.A.B.
    • This option is missing the angular frequency (ω), which is necessary for calculating the maximum emf.
  • Option 3: N.A.B.R.
    • This option incorrectly includes resistance (R), which does not influence the maximum emf generated.
  • Option 4: N.A.B.ω
    • This option correctly includes the number of turns (N), the area of the coil (A), the magnetic field strength (B), and the angular frequency of rotation (ω).

Therefore, the correct answer is option 4: N.A.B.ω.