⚛️ Physics · Alternating Current · NEET & JEE

An AC generator has E<sub>0</sub> = NBAω. If the number of turns is increased by 50%, the coil area is doubled, and the angular speed is reduced to half while the magnetic field remains unchanged, how does the peak emf change?

Answer: It becomes 1.50 times.

A It becomes 1.25 times
B It becomes 1.50 times
C It becomes 2.00 times
D It remains unchanged

Correct answer: B. It becomes 1.50 times

Explanation: The new emf factor is 1.5×2×0.5 = 1.5. Therefore the peak emf becomes 1.5 times its original value.

In a pure inductor the current lags the voltage by 90° (energy is briefly stored in the magnetic field before current responds); in a pure capacitor the current leads the voltage by 90° (current must flow to build up charge before voltage rises) - the mnemonic "ELI the ICE man" keeps these straight.

Concept context

AC circuits, impedance, LCR series circuit, resonance, transformers, and power factor.

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An AC generator has E<sub>0</sub> = NBA&omega;. If the number of turns is increased by 50%, the coil area is doubled, and the angular speed is reduced to half while the magnetic field remains unchanged, how does the peak emf change?

Concept context

More Alternating Current questions

An AC generator has E<sub>0</sub> = NBAω. If the number of turns is increased by 50%, the coil area is doubled, and the angular speed is reduced to half while the magnetic field remains unchanged, how does the peak emf change?