Problem 1.

A car radio draws 0.25 A of current in auto’s 12 V electrical system.

a) How much electric power does the radio use?

b) What is the effective resistance of the radio?

Problem2.

Two resistors with values of 35 Ω and 25 Ω respectively are connected in series and hooked to a 12 V battery.

1. How much current is in the circuit?
2. How much power is expanded in the circuit?
Problem 3.

A student in a laboratory connects a 10 ohm resistor, a 15 ohm resistor and a 25 ohm resistor in series and then connects the arrangement to a 50 V DC source. How much power is expended in the circuit?

Problem 4.

A flashlight uses batteries that add up to 4.5 V and has a power output of 0.90 W.

(a) How much current is drawn from the batteries?

(a) What is the effective resistance of the flashlight?

Problem 5.

How much does it cost to run a 1000-W hair dryer for 15 minutes each day for one month (30 days) at a cost of 10 ¢ per kWh?

Problem 6.

A refrigerator using 1500 W runs one fourth of the time. How much does the electricity cost to run the refrigerator each month (30 days) at 15 cents per kWh?

Problem 7.

A 100-W light bulb is turned on. It has an operating voltage of 120 V.

1. How much current flows through the bulb?
2. What is the resistance of the bulb?
3. How much energy is used each second?

Answer rating: 100% (QA)

The detailed answer for the above question is provided below Solution The equation that gives the electric power consumed by a circuit with a voltage ... View the full answer