An inductor-resistance -battery circuit is switched on at t = 0. find the emf of the battery in one time constant .

Explanation

To solve the problem of finding the EMF of the battery in an inductor-resistor circuit at one time constant, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Circuit Components**:
- We have a circuit consisting of a battery with EMF \( V \), an inductor with inductance \( L \), and a resistor with resistance \( R \). The switch is closed at \( t = 0 \).

2. **Current in the Circuit**:
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