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A circuit connected to an ac source of emf e = e0 sin (100t) with t in seconds, gives a phase difference of π/4 between the emf and current. Which of the following circuits will exhibit this? (1) R L circuit with R = 1 kΩ and L = 10 mH (2) R L circuit with R = 1 kΩ and L = 1 mH (3) R C circuit with R = 1 kΩ and C = 1 μF (4) R C circuit with R = 1 kΩ and C = 10 μF

1. R L circuit with R = 1 kΩ and L = 10 mH
2. R L circuit with R = 1 kΩ and L = 1 mH
3. R C circuit with R = 1 kΩ and C = 1 μF
4. R C circuit with R = 1 kΩ and C = 10 μF

Correct answer: R L circuit with R = 1 kΩ and L = 10 mH

Solution

The correct option is an R-L circuit with a larger inductance (10 mH), which results in a greater inductive reactance. This leads to a phase difference of π/4 between the emf and current, as the impedance of the circuit allows for this specific phase relationship.

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