A voltmeter is used to read the potential difference accross the poles of a battery.
The battery is rated at 20 V. The battery is connected in a series to a switch, an ammeter and a resistor. When the switch is open, the ammeter reads 0.0A and the voltmeter reads 20.0 V. When the switch is closed the ammeter reads 1.0A and the voltmeter reads 19.0V. Which is likely to be the explanation for the result?
a. The ammeter has too little resistance
b. the voltmeter has too much resistance
c. the battery has an internal resistance of 1.0 ohm
d. the resistor in the circuit has a resistance of 20.0 ohm