Adding Resistors
A circuit contains three resistors in series. A 20 ohm, 30 ohm and 50 ohm resistor. What is the total resistance of the circuit?
100 ohms
A resistance of 30Ω is placed in a circuit with a 90 volt battery. What current flows in the circuit?
3 A
Four identical resistors are placed in series in a circuit. The resistance of all four resistors together is 36 Ω.What is the resistance of each resistor individually?
9 ohms
A 20 W light bulb uses how many joules of energy if left on for two hours?
144,000 J
An electric kettle has a power rating of 2400 W. It has been used to keep water warm for 2 hrs. Calculate the cost of the electricity used if each unit costs is 17 cents.
$0.82
A circuit contains two resistors in parallel. A 3 ohm and 6 ohm resistor. What is the total resistance of the circuit?
2 ohm
The resistance of an electric stove burner element is 11 ohms. What current flows through this element when it runs off a 220 volt line?
20 A
A circuit consists of two resistors in series, 7 and 5 ohms, with 3 ammeters placed at different points in the circuit. The first ammeter reads 4 A. What is the current at the third ammeter?
4A
Calculate the resistance of a 1000 W microwave oven that gets plugged into to a 110-V outlet.
12.1 ohms
A fan has a power rating of 3600 W. It has been used to keep room cool for 720 mins. Calculate the cost of the electricity used if each unit costs is 20 cents.
$8.64
A circuit contains 3 resistors in parallel, a 20 ohm, 50 ohm and 100 ohm resistor. What is the total resistance of the circuit?
12.5 ohms
What is the resistance of a lamp that is connected to a 110 voltage source that draws 2 amps of current?
55 ohms
A student sets up a parallel circuit with three identical resistors. The value of the total current is 15 A.What is the value of ?
5 A
How many joules of energy would a 40 W light bulb use in 30 seconds?
1200 J
An electric heater draws 1100 W of power. Electricity costs 8¢ per kW•h. How much does it cost to operate the heater 3.0 h a day for 30 days? $7.92
$7.92
A combination circuit contains three resistors. The 2 ohm and 4 ohm resistors are in series with each other, while a 12 ohm resistor is in parallel to them both. What is the total resistances of the circuit?
4 ohms
A 12 V battery causes a current of 3 A to flow through a resistor. What is the value of the resistance.
4 ohms
A circuit contains two resistors connected in parallel to a battery. If the potential difference (voltage) across the 3 Ω resistor is 18 V, what is the potential difference across the 6 Ω resistor?
18 V
A bulb is plugged into a 120 Volt outlet. The resistance of the bulbs is 330 ohms.Calculate both the current and power of the bulb.
0.36 A and 43.2 W
What is the cost of running a 240 W fridge 24 hrs a day for a month (30 days) if the power company charges 15c per kWh?
$25.92
A combination circuit has 4 resistors. The 5 ohm and 8 ohm resistors are in series, while the 4 ohm and 12 ohm resistors are in parallel with each other. What is the total resistance of this circuit?
16 ohms
A parallel circuit has x3 3 ohm resistors and a voltage of 12 v. What is the current of running across the battery?
4 A
A student sets up a parallel circuit with 4 and 12 ohm resistor. The value of the current across the battery is 8 A and the value of current across the 4 ohm resistor is 6 A. What is the current across the 12 ohm resistor?
2 A
A 60 mW lamp is connected to a 12 V battery and left on for 30 minutes. How much charge passes through the lamp over this time?
A toaster is used an average of 5.0 h a month. The toaster draws 8.0 A of current from a 110 V outlet.
If electricity costs 8¢ per kW•h, how much will it cost to operate the toaster for one year?
$4.22