Electric Circuits Practice
Exercises
Electric Current
1. A current of 3.60A flows for 15.3 s through
a conductor. Calculate the number of
electrons that pass through a point of the
conductor during this time.
2. How long would it take 2.0 × 1020 electrons
to pass through a point in a conductor if the
current was 10.0A?
3. Calculate the current through a conductor if
a charge of 5.60C passes through a point in
the conductor in 15.4s.
4. What potential difference is required across
a conductor to produce a current of 8.00A if
there is a resistance in the conductor of
12.0Ω?
5. What is the heat energy produced in a
conductor in 25.0s if there is a current of
11.0A and a resistance in the conductor of
7.20Ω?
6. A particular conductor produces 1.50 × 102 J
of heat in 5.50 s. If the current through the
conductor is 10.0A, what is the resistance of
the conductor?
7. What is the current through a 4.00 × 102 W
electric appliance when it is connected to a
1.20 × 102 V power line?
8. a) When an electric appliance is connected
to a 1.20 × 102 V power line, there is a
current through the appliance of 18.3A.
What is the resistance of the appliance?
b) What is the average amount of energy
given to each electron by the power line?
9. a) What potential difference is required
across an electrical appliance to produce a
current of 20.0A when there is a resistance
in the appliance of 6.00 Ω?
b) How many electrons pass through the
electrical appliance every minute?
10. If electricity cost $ 0.060 per kilowatt hour,
what does it cost to operate a 1.0 × 103 W
appliance for 5.0h?
11. A student forgets to turn off a 6.00 × 102 W
block heater of a car when the weather
turns warm. If 14 h goes by before he shuts
it off, how much energy is used by the
heater?
12. A 45 kg object is lifted vertically at a
constant speed to a height of 9.0 m by a 7.5
× 102W electric motor. If this motor is 25%
efficient in converting electric energy to
mechanical energy, how long does the
motor take to life the object?
Electric Circuits
1. What are the values for I2 and I3 in the
circuit?
2. What is the value of I3 in the circuit?
3. What is the value of V2 in the circuit?
