Electricity - Ohm's Law

The statement which correctly represents Ohm’s law:

• V = IR

• V = R/I

• R = VI

• I = R/V

A 10 ohms resistor is powered by a 5-V battery. The current flowing through the source is:

• 10 A

• 50 A

• 2 A

• 0.5 A

An electric kettle with 50-Ω heat element is powered by a 230-V wall outlet. The current flowing through kettle is:

• 0.217 A

• 4.6 A

• 10.86 A

• 11500 A

If doubling the voltage across a resistor doubles the current through the resistor, then

• The resistor value decreased

• The resistor value did not change

• The resistor value increased

• It is impossible to determine the change in the resistor value

If the voltage across a fixed value of resistance is increased five times, what does the current do?

• It increases by a factor of five.

• It decreases by a factor of five.

• It stays the same.

• Not enough information

If the resistance in a circuit with constant voltage increases, the current will

• Increase

• Decrease

• Its stays the same

• Not eneough information

In a _________ circuit, the total resistance is greater than the largest resistance in the circuit.

• Series

• Parallel

• Either series or parallel

• Neither series nor parallel

• The resistors are connected in parallel because the same current flows through all three resistors.

• The resistors are connected in parallel because different current flows through all three resistors.

• The resistors are connected in series because the same current flows through all three resistors.

• The resistors are connected in series because different current flows through all three resistors.

Give a verbal expression for Ohm’s law.

• Ohm’s law says that the current through a resistor equals the voltage across the resistor multiplied by the resistance of the resistor.

• Ohm’s law says that the voltage across a resistor equals the current through the resistor multiplied by the resistance of the resistor.

• Ohm’s law says that the resistance of the resistor equals the current through the resistor multiplied by the voltage across a resistor.

• Ohm’s law says that the voltage across a resistor equals the square of the current through the resistor multiplied by the resistance of the resistor.

Two identical resistors are connected in parallel across the terminals of a battery. If you increase the resistance of one of the resistors, what happens to the current through and the voltage across the other resistor?

• The current and the voltage remain the same.

• The current decreases and the voltage remains the same.

• The current and the voltage increases.

• The current increases and the voltage remains the same.