A thin copper rod of radius 1mm having an electrical resistance of `100 Omega` is connected to battery of emf 12 volts and negligible internal resistance through a wire of negligible resistance. Calculate current density in the wire. Also , calculate the number of electrons entering one and of the rod per seconds.

Explanation

To solve the problem, we will follow these steps:

### Step 1: Calculate the Current (I) using Ohm's Law
Ohm's Law states that \( V = I \cdot R \), where:
- \( V \) is the voltage (emf of the battery),
- \( I \) is the current,
- \( R \) is the resistance.

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