Deck 6: Parallel Circuits

Question 1

Figure 6-4
Given the circuit in Figure 6-4, find the total current It).

A) 0.187 A
B) 24.8 mA
C) 0.024 A
D) 375 mA

Answer 1

375 mA

Question 2

Given the circuit in Figure , what is the total equivalent) resistance of the circuit?

A) 100 Ω
B) 600 Ω
C) 300 Ω/3
D) 100 Ω × 3
E) A and C are correct.

Answer 2

A and C are correct.

Question 3

Figure 6-4
Given the circuit in Figure 6-4, find the current through R2.

A) 0.187 A
B) 0.25 A
C) 0.125 A
D) 24.8 mA

Answer 3

0.125 A

Question 4

The voltage drop across each resistance in a parallel circuit is equal to the applied voltage.

Question 5

The total equivalent) resistance in a parallel circuit is always less than the lowest value resistor in the circuit.

Question 6

Each resistor in a parallel circuit demands a current I = V/R), and is independent of all other resistors in parallel with it.

Question 7

Given the circuit in Figure , what is the resistance value of R2?

A) 220 Ω
B) 20 kΩ
C) 1.5 kΩ
D) 1 kΩ

Question 8

When two or more components are connected across the same voltage source, they are in parallel.

Question 9

Given the circuit in Figure 6-5, what is the current flowing through R2?

A) 0.5 mA
B) 1.5 mA
C) 1.0 mA
D) 500 mA

Question 10

Figure 6-6
Given the circuit in Figure 6-6, find the total current.

A) 0.3 A
B) 0.02 A
C) 0.2 A
D) 0.3 mA

Question 11

Figure 6-4
Given the circuit in Figure 6-4, what is the voltage drop across R2?

A) 0.25 A
B) 10 V
C) 3.3 V
D) 25.0 V

Question 12

The total power taken from the power supply, and dissipated by the resistors in a parallel circuit, is the sum of the powers dissipated by each resistor in the circuit.

Question 13

Figure 6-7
Given the circuit in Figure 6-7, find the total power.

A) 0.125 W
B) 310 mW
C) 187 mW
D) 0.035 W

Question 14

If one of the resistors opens in a parallel circuit, total resistance of the circuit will increase.

Question 15

A junction is any point in a circuit where two or more circuit paths come together.

Question 16

A parallel connection provides two or more paths for current to flow.

Question 17

A parallel circuit is also used as a current divider.

Question 18

When parallel resistors are of three different values, the smallest resistor will dissipate the greatest amount of power.

Question 19

Figure 6-7
Given the circuit in Figure 6-7, select a minimum wattage rating for R2.

A) 5 W
B) 1/2 W
C) 1 W
D) 1/4 W

Question 20

Figure 6-4
Given the circuit in Figure 6-4, find the current through R1.

A) 24.8 mA
B) 0.25 A
C) 0.024 A
D) 0.187 A

Question 21

Circuit analysis should reveal that the largest resistance in a parallel circuit has the:

A) least voltage
B) least current
C) most current
D) most voltage

Question 22

To find one branch current of two resistors in shunt, the:

A) total current is multiplied by the ratio of the other branch resistor, divided by the sum of the branch resistances.
B) product of both is divided by their sum.
C) product of both is divided by their difference.
D) total current is divided by the ratio of the other branch resistor divided by their sum.

Question 23

If 10 A of current entered a two branch junction, and 2 A flowed into Branch "A", how much current will flow in branch "B"?

A) 12 A
B) 10A
C) 5 A
D) 8 A

Question 24

The total resistance of two resistors in parallel is equal to the:

A) value of one branch resistor divided by the sum of their R values.
B) product of their R values divided by the sum of the two resistors.
C) source voltage divided by any of the two branch resistors.
D) sum divided by the product of the two resistors.

Question 25

What devices can be used to find shorts in a circuit?

A) pulser
B) potentiometer
C) current tracer
D) both A and C
E) none of the above

Question 26

In a parallel resistive circuit:

A) there is more than one current path between two points.
B) the total branch power exceeds the source power.
C) the voltage applied divides between the branches.
D) the total circuit conductance is less than the smallest branch conductance.

Question 27

What is the total resistance of a 3 kΩ, 4 kΩ, and 12 kΩ resistors that are in parallel with each other?

A) 6.3 kΩ
B) 19 kΩ
C) 2 kΩ
D) 1.5 kΩ

Question 28

The general current divider equation used to find a branch current is equal to the:

A) total resistance divided by the product of that branch resistance and the total current.
B) resistance total divided by that branch resistor, multiplied by the total current.
C) branch voltage divided by the total resistance.
D) branch resistance divided by the total resistance, multiplied by the total current.

Question 29

Four eight-ohm speakers are connected in parallel to an audio power amplifier. The amplifier can supply a maximum drive output voltage of fifteen volts. How much audio power must the amplifier be able to deliver to the speakers when outputting this maximum voltage?

A) 225 W
B) 112.5 W
C) 56 W
D) 28 W

Question 30

Given the circuit in Figure , what is the total equivalent) resistance?

A) 520 Ω
B) 6.4 kΩ
C) 5.2 kΩ
D) 4.7 kΩ

Question 31

Given the circuit in Figure 6-9, what voltage must be applied between points A and B to get the circuit current of 2.75 mA?

A) 1.43 V
B) 4.7 V
C) 14.3 V
D) 2.75 V

Question 32

While checking a circuit for current flow, it is noted that R1 current has increased; since it is in parallel with R2, the problem is:

A) R1 is shorted
B) R1 is open
C) R2 is shorted
D) R2 is open

Question 33

Kirchhoff's law for parallel circuits states that the:

A) total circuit resistance is less than the smallest branch resistor.
B) sum of currents into a junction is equal to the difference of all the branch currents.
C) sum of all branch voltages equal zero.
D) sum of the total currents flowing out of a junction equals the sum of the total currents flowing into that junction.

Question 34

Given the circuit in Figure , if R3 is changed to 100 Ω, the total circuit current will:

A) increase
B) remain the same
C) decrease
D) double

Question 35

To determine the value of a resistor to place in shunt with a known resistor to obtain a certain value of the total parallel combination:

A) multiply the desired value by the known value, then divide this product by their difference.
B) subtract the known from the desired total.
C) multiply the desired by the known, then divide this product by their sum.
D) add the desired to the known.

Question 36

The voltage across any branch of a parallel circuit:

A) is inversely proportional to total circuit resistance.
B) varies as the total current varies.
C) is dropped in proportion to each branch resistance.
D) is equally applied to all branch conductances.

Question 37

If two lamps, L1 and L2, are connected in parallel and L1 opens, what would happen?

A) Both lamps would be on
B) L1 would be on and L2 would be off.
C) Both lamps would be off
D) L1 would be off and L2 would be on.

Question 38

Given the circuit in Figure 6-9, what is the output current Iout)?

A) 2.75 mA
B) 1.25 mA
C) 0.01 A
D) Iin/3

Question 39

Shunt resistors:

A) are connected in parallel for higher current range settings on a meter.
B) are not used in ammeters.
C) are connected in series for higher current range settings on a meter.
D) are resistors connected in series.

Question 40

The total resistance of a parallel circuit:

A) equals the sum of the total circuit conductance.
B) is always greater than the largest branch resistance.
C) equals the sum of all the branch resistances.
D) is the inverse of the total circuit conductance.