What is electromotive force (emf)? What is its SI unit? If a source of emf 12 V is connected to a resistor of resistance 4 Ω, then what will be the current flowing in the circuit? Neglect internal resistance of the source.

Electromotive force (emf) is the potential difference or voltage produced by a source such as a battery or generator. It is the driving force that pushes the electric charges through a circuit. The SI unit of emf is volts (V).

In this scenario, a source of emf with a value of 12 V is connected to a resistor with a resistance of 4 Ω. To find the current flowing in the circuit, we can use Ohm's Law, which states that the current (I) flowing through a circuit is equal to the voltage (V) divided by the resistance (R).

Using Ohm's Law, we can calculate the current as follows:

I = V / R

Substituting the given values:

I = 12 V / 4 Ω

Simplifying the equation:

I = 3 A

Therefore, the current flowing in the circuit is 3 amperes (A).