Resistance and Ohm's Law

What does the equation V=IR represent in electrical circuits?

• Voltage equals current divided by resistance

• Voltage equals the square of current times resistance

• Voltage equals current times resistance

• Voltage equals current plus resistance

If a circuit has a current of 1.5 amps and a total resistance of 6 ohms, what is the potential difference across the cell/battery?

• 9 volts

• 4 volts

• 7.5 volts

• 4.5 volts

How do you calculate resistance if you know the voltage and current?

• Add voltage and current

• Divide voltage by current

• Subtract voltage from current

• Multiply voltage by current

What happens to the current if the voltage increases while resistance remains constant?

• Current increases

• Cannot be determined

• Current remains constant

• Current decreases

In a circuit, if the resistance remains constant and the voltage is doubled, what happens to the current?

• It is halved

• It remains the same

• It is doubled

• It becomes zero

In a graph of current vs. potential difference, what does a straight line indicate?

• No resistance

• Increasing resistance

• Constant resistance

• Decreasing resistance

What does a less steep line in a current vs. potential difference graph indicate?

• Intermittent resistance

• No change in resistance

• Lower resistance

• Higher resistance

What effect does increasing temperature have on resistance in a circuit?

• Increases resistance

• No effect on resistance

• Initially decreases then increases

• Decreases resistance

A power supply with a potential difference of 6V is connected in series with an ammeter and a 10 Ohm resistor. What is the potential difference across the resistor

• 60 V

• 1.67 V

• 6 V

• Impossible to know without knowing the current

A current of 2 Amps flows through a 10 Ohm resistor. What is the potential difference across the resistor

• 5 V

• 20 V

• 0.2 V

• 12 V