Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.

Please verify your account before proceeding.

In this lesson, we will learn how to use the formula V = IR (Ohm's law) to calculate the resistance in simple electronic circuits.

Q1:

A resistor is placed in a circuit with an adjustable voltage source. Measurements of the voltage across and the current through the resistor are shown in the accompanying graph. Find the resistance of the resistor.

Q2:

A resistor of resistance 1.8 kΩ is connected across a battery of emf 5.0 V. What is the current through the resistor?

Q3:

Calculate the effective resistance of a pocket calculator that has a 1.35 V battery if the current through the calculator is 0.200 mA.

Q4:

What is the voltage supplied to a 1.44-kW-power short circuit through a 0.100- Ω resistance?

Q5:

Currents of 0.06 A can potentially kill people by making their heart fibrillate (beat in an uncontrolled manner).

What voltage can produce 0.2 A of current through a dry human body with an average resistance of 100 kΩ?

A human body is made wet by heavy rain. The body has an average resistance of 100 Ω. What voltage can induce fibrillation in these circumstances?

Q6:

A resistor is connected in series with a power supply of 35 V, producing a current in the resistor of 0.25 A. What is the resistance of the resistor?

Q7:

An indicator light on a DVD player has a resistance of 300 Ω and the current in the light is 55.0 mA. How many volts are supplied to operate the light?

Q8:

What is the current through the bulb of a flashlight that has a resistance of 5.0 Ω if the flashlight is powered by a battery with an emf of 4.5 V?

Q9:

A 58.0 V battery is connected across a resistor combination consisting of a 14.0 Ω resistor and a 46.0 Ω resistor.

Find the current in the 14.0 Ω resistor when the resistors are connected in series.

Find the current in the 46.0 Ω resistor when the resistors are connected in series.

Find the power dissipated by the 14.0 Ω resistor when the resistors are connected in series.

Find the power dissipated by the 46.0 Ω resistor when the resistors are connected in series.

Find the current in the 14.0 Ω resistor when the resistors are connected in parallel.

Find the current in the 46.0 Ω resistor when the resistors are connected in parallel.

Find the power dissipated by the 14.0 Ω resistor when the resistors are connected in parallel.

Find the power dissipated by the 46.0 Ω resistor when the resistors are connected in parallel.

Don’t have an account? Sign Up