A 12V battery is connected across two resistors, R1=100Ω and R2=300Ω, joined in series. A voltmeter of internal resistance 3kΩ is used to measure the potential difference across R2.
a. Calculate the true potential difference across R2 when the voltmeter is not connected.
b. Determine the reading of the voltmeter when it is connected across R2.
c. Find the percentage error introduced by the voltmeter.