The DC emf is 24 V when connected to an external resistance of 10 Ohm, the current

The DC emf is 24 V when connected to an external resistance of 10 Ohm, the current in the circuit was 2 A. Determine the resistance of the current source.

EMF = 24 V.

R = 10 ohms.

I = 2 A.

r -?

Let us write Ohm’s law for a complete closed circuit: I = EMF / (R + r), where EMF is the electromotive force of the current source, R is the external resistance of the circuit, r is the internal resistance of the current source, I is the current strength.

The internal resistance of the current source r will be expressed by the formula: r = (EMF – I * R) / I.

r = (24 V – 2 A * 10 Ohm) / 2 A = 2 Ohm.

Answer: the internal resistance of the current source is r = 2 A.