Series, Parallel & Combined Circuits Handout
1. Use the following circuit to determine:
1.1
Current intensity (total) if R1 = 5Ω, R2 = 15Ω, R3 = 20Ω, and ε = 20 V.
1.2
Potential difference at both sides of each resistor. Place each voltmeter on circuit.
1.3
What type of circuit is this? Why?
2. Use the following circuit to determine:
2.1
The value of R2 if R1 = 25Ω, R3 = 15Ω, ε = 25 V and the ammeter reads 0.5 A.
2.2
The value of voltage across the terminals of R2.
3. In a home, each light is controlled with a separate switch. If a light burns out, the other
lights remain on. What type of circuit is then used for these lights? Why?
4. For the following circuits, calculate the current intensity for each resistor (light bulb), the
total current intensity, the voltage for each resistor (light bulb), and the equivalent (total)
resistance. Indicate the type of circuit, and explain your answer. Also, place the necessary
voltmeters to obtain the values you just calculated, as well as the ammeters for all the
values you just calculated.
5. Ahmed estimates the equivalent resistance of a circuit to be 7Ω. The circuit comprises
four parallel resistors, measuring 5Ω, 8Ω, 10Ω and 15Ω each. Mishiko, insists that it is
impossible, and he has made a mistake, why does she think so?
6. If we connect another 10Ω resistor parallel to R2 (question 2), will the value of total
intensity change (increase or decrease). Why?
7. You have a small electric motor with 1Ω resistance, a 6V battery, two 1Ω resistances, one
4Ω resistance and one 12Ω resistance. If the motor requires 1A current to function, why
can you not connect the motor directly to the battery?
7.1- Draw two circuits that would allow you to have the motor work at the desired current
value (1A). Note: one (or both) circuit(s) may not need that you use all the resistors
8. A meteorology station located on an isolated mountain records daily readings. The
instruments are powered by a battery composed of several cells connected in parallel.
What is the advantage of this type of power supply? What would you do to if it were
discovered that the components were not working properly due to a lack of energy
supply?
9. According to the following circuit:
9.1
Determine the values of I1 and I2 if you know that It = 5A and I3 = 2A.
9.2
Determine the value of V1 and V3 if the emf of the cell is 6V and V2 = 4V
9.3
Determine the equivalent resistance of the circuit (total).
10. Complete the data below:
10.1
I1 = 6 A
I2 = 2 A
I3 = ___
I4 = 4 A
V1 = 3 V
V2 = ___
V3 = 8 V
V4 = 7 V
Calculate the equivalent (total) resistance of the circuit.