Understanding Ohm's Law

Nora is conducting an experiment in her physics class to understand the relationship between voltage, current, and resistance. What is the mathematical equation representing this relationship?

A household electric iron has a resistance of 55.0 Ω. If 5.5 A of current is flowing through the resistance, then the voltage available between the two terminals is _____ volt/s.

An equipment has a resistance of 50.0 Ω. If 160 volts is the potential difference between the two terminals, how much current (in amperes) is flowing through the resistance?

A 3.5 mm in diameter silver wire moved a charge of magnitude 500 C in 1 hour. Determine the current in the silver wire and the resistance if the potential difference is 75.5 V.

• 0.123 A, 612 Ω

• 0.138 A, 547 Ω

• 0.139 A, 543 Ω

• 0.142 A, 531 Ω

According to Ohm’s Law, if Zoe is using a circuit with a constant resistance and she increases the current, what happens to the voltage?

• increases

• decreases

• remains the same

• becomes zero

If the resistance in a circuit doubles while the voltage remains constant, what happens to the current?

• It doubles

• It remains the same

• It is cut in half

• It quadruples

Which of the following correctly describes the relationship between voltage, current, and resistance?

• If voltage increases and resistance remains the same, current decreases.

• If resistance increases while voltage remains the same, current decreases.

• If resistance decreases while voltage remains the same, current also decreases.

• If voltage and resistance both increase, current always increases.

A copper wire with a diameter of 2 mm carries a current of 3 A. If the length of the wire is 100 m, calculate the resistance of the wire if the resistivity of copper is 1.68 x 10^-8 Ω·m.

• 0.0080 Ω

• 0.0053 Ω

• 0.0068 Ω

• 0.0072 Ω

What is the resistor value in the given circuit?

• 200 Ω

• 1 kΩ

• 2 kΩ

• 4 kΩ

If the voltage in the given circuit was cut in half, what would the current equal?

• 10 mA

• 30 mA

• 60 mA

• 90 mA