Question

When a 20.0-ohm resistor is connected across the terminals of a 12.0-V battery, the voltage across the terminals of the battery falls by 0.300 V. What is the internal resistance of this battery?

a. 3.60 Ω
b. 0.51 Ω
c. 0.30 Ω
d. 1.56 Ω
e. 0.98 Ω

Answer 1

B. 0.51 ohms

Step-by-step explanation:

Our data is as follows:

Resistor R = 20.0ohms

V1 = 12 volts

V2 = 0.300 V

We are to get the internal resistance of this battery

Now,

I = change in voltage/R

Change in voltage = v1-v2

= 12-0.300

= 11.7

Then,

I = 11.7/20

= 0.585Ri

Now

O.300 = 0.585Ri

Ri = 0.300/0.585

= 0.51 ohms

This is therefore the internal resistance of the battery.

Thank you!