Question

PLEASE HELP URGENT

A battery has terminal voltage of 12v for a circuit with a 20 ohm resistor. What is the EMF of the battery if it has an internal resistance of 0.5 ohm's?

Answer 1

The EMF of the battery is 11.5 volts.

Answer 2

The EMF of the battery can be calculated using the following formula:

EMF = V + Ir

where:

EMF = electromotive force (unknown)

V = terminal voltage = 12 V

I = current flowing through the circuit (unknown)

r = internal resistance = 0.5 Ω

To find I, we can use Ohm's law:

V = IR

where R is the total resistance of the circuit (including the internal resistance), so:

R = 20 Ω + 0.5 Ω = 20.5 Ω

Rearranging Ohm's law to solve for I, we get:

I = V / R

I = 12 V / 20.5 Ω

I ≈ 0.585 A

Now we can substitute the values of V, I, and r into the first formula:

EMF = V + Ir

EMF = 12 V + 0.585 A × 0.5 Ω

EMF ≈ 12.2925 V

Therefore, the EMF of the battery is approximately 12.2925 volts.