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Worksheets4.3.2 Series and Parallel Circuits
Total questions: 104
Worksheet time: 2hrs 38mins
In a series circuit, how does current behave through the components?
It is the same everywhere in the circuit.
It increases after each component.
It splits and recombines across branches.
It is zero across the power supply.
In a parallel circuit, what happens to the potential difference (voltage) across each branch?
It is shared between branches, so each branch gets a fraction.
It is the same across each branch, equal to the battery voltage.
It increases with the number of branches.
It depends only on the resistance of the branch with the smallest current.
Which statement best distinguishes series from parallel connections?
Series: current splits between components; Parallel: voltage is shared between branches.
Series: voltage is the same across all components; Parallel: current is the same in every branch.
Series: current is the same everywhere, voltage is shared; Parallel: current is shared between branches, voltage is the same across each branch.
Series: both current and voltage are the same everywhere; Parallel: both are shared.
A circuit has two identical bulbs connected so that the current through each bulb is different but the voltage across each bulb equals the battery voltage. What connection does this indicate?
Series connection of bulbs
Parallel connection of bulbs
Short circuit across the battery
Open circuit with one bulb removed
A student connects three resistors. The ammeter reading is 0.40 A at several points in the loop, but individual voltmeter readings across each resistor add up to the battery’s voltage. What is the most reasonable conclusion about how the resistors are connected?
They are connected in series because current is uniform and voltage is shared across components.
They are connected in parallel because current is split and voltage is the same on each branch.
They are mixed series-parallel because current is uniform but voltage is uniform across each resistor.
The connection cannot be determined from current and voltage data.
In a series circuit, what is true about the current at different points along the loop?
It is the same at every point
It is largest near the battery and smallest near the last component
It alternates direction in each component
It halves after each component
Which statement best describes current in a parallel circuit with two branches?
Current is identical in all branches and equals the source current
The current from the source is larger than the current in each individual branch
The current in each branch is larger than the current from the source
No current flows through branches with equal resistance
Two identical cells, each of e.m.f. E, are connected in series. Neglecting internal resistance, what is the combined e.m.f.?
E
2E
E/2
E2
For two resistors R1 and R2 connected in series, which expression gives the combined resistance?
R1 + R2
(R1 R2)/(R1 + R2)
|R1 − R2|
(R1 + R2)/2
For two resistors R1 and R2 connected in parallel, which statement is correct about the combined resistance?
It equals R1 + R2
It is greater than either resistor alone
It is less than that of either resistor by itself
It equals (R1 + R2)/2
What is the advantage of connecting lamps in parallel in a lighting circuit?
All lamps share the same current so none can burn out
Each lamp receives full supply p.d., and one failing does not extinguish the others
Total power used is minimized regardless of lamp ratings
Parallel wiring eliminates the need for switches
Which p.d. relationship holds for a series circuit?
The total p.d. across the components equals the sum of the individual p.d.s across each component
Each component has the same p.d. as the supply
The total p.d. is the product of the individual p.d.s
The total p.d. equals the largest single component p.d.
In a parallel arrangement of resistances, what is the potential difference across each branch compared to the arrangement as a whole?
Each branch has half the total p.d.
Each branch has the same p.d. as the arrangement
Branches share p.d. in proportion to resistance
Only the lowest-resistance branch has the total p.d.
Which statement correctly applies conservation of charge at a junction in a parallel circuit?
The sum of currents entering a junction equals the sum of currents leaving the junction
Current builds up at a junction, increasing over time
The leaving currents must be less than the entering currents
Currents in all branches must be equal regardless of resistance
Two resistors of 6 Ω and 3 Ω are connected in parallel. Using the syllabus skill for combined resistance in parallel, which combined resistance is correct?
9 Ω
4.5 Ω
2 Ω
1 Ω
A series circuit has three resistors with p.d.s of 2 V, 3 V, and 5 V across them. What is the total supply p.d. according to the stated series rule?
5 V
8 V
10 V
15 V
Which list correctly names the common ways components can be connected to form electrical circuits?
Only series connections
Series, parallel, or a mixture of both
Only parallel connections
Random arrangements without defined types
What defining feature characterizes a series circuit according to the introduction?
It has multiple independent electrical paths
It has only one electrical path through all components
It allows components to be bypassed without breaking the circuit
It requires at least two batteries connected in parallel
A student traces from one side of the battery through each component to the other side without lifting a finger. What does this action demonstrate?
The circuit is parallel because each branch is separate
The circuit is open because the path is interrupted
The circuit is series because there is a single continuous path
The circuit has mixed connections because some parts are bypassed
In the series circuit diagram with a 6 V battery and a single loop, which statement about current is consistent with the description?
Current splits equally among branches
The same current flows through each component in the loop
Current is highest at the battery and lowest at the lamp
Current reverses direction after the ammeter
Consider the activity diagram showing three lamps in series powered by a 6 V source. The bulbs appear much dimmer. What is the most appropriate explanation?
Adding lamps in series reduces total resistance, increasing current and brightness
Adding lamps in series increases the total resistance, reducing current so each lamp receives less power
Adding lamps in series increases voltage across each lamp, making them dimmer
Adding lamps in series disconnects the battery, preventing current
Which statement best compares series and parallel circuits?
Series circuits have one path; parallel circuits provide multiple paths
Both series and parallel circuits have one path
Parallel circuits have no defined paths
Series circuits require alternating current while parallel circuits require direct current
According to the guidelines for successful circuit diagrams, which tool should you use to ensure neat, accurate lines when drawing?
A ruler and pencil
A freehand marker
Colored pens only
A compass and protractor
Which practice best follows the rule for drawing wires in circuit diagrams?
Draw wires as straight lines with corners at right angles
Sketch wires as curved paths to show flow
Use zigzag lines for all wires to save space
Leave wires unconnected if components are close
You finish a circuit diagram. What is the final quality check recommended by the guidelines?
Confirm all components are correctly drawn and properly joined in the circuit
Add decorative symbols to label each wire
Erase right-angle corners to make smooth turns
Shade components to indicate their material
In the same series circuit, if one ammeter reads 40.0 mA, what should another ammeter placed elsewhere in the loop read?
40.0 mA
20.0 mA
Depends on proximity to the battery
0 mA unless placed before a lamp
Which statement best explains why all ammeters in the series circuit display 40.0 mA?
Current has only one path in a series circuit, so the same charge flow passes every component.
Voltage is the same across all components in series, forcing equal current.
Ammeter internal resistance sets the circuit current to a fixed value.
The lamps are identical, so their currents match regardless of circuit type.
In a series circuit, which statement about electric current is correct?
The current is the same at all points in the circuit.
The current increases after each resistor in the circuit.
The current is zero at the power source and maximum at the last component.
The current alternates between high and low values at different points.
Which mathematical expression correctly represents the current behavior in a series circuit with multiple components?
I1 + I2 + I3 = 0
I1 = I2 = I3 = I4
I = I1 + I2 + I3
I1 = I2 + I3 + I4
In a series circuit, how is the total voltage across the circuit related to the voltages across individual components?
The total voltage equals the product of individual voltages.
The total voltage is the same as the largest single voltage drop.
The total voltage equals the sum of the individual voltage drops (V = V1 + V2 + …).
The total voltage is always zero regardless of components.
Which observation about voltage in a series circuit is accurate?
Voltage is the same at all points in the circuit.
Voltage is not the same at all points; it divides across components.
Voltage increases uniformly after each resistor.
Voltage only appears across the first component.
For resistors connected in series, which formula gives the equivalent resistance?
R = R1 − R2 − …
R = 1/R1 + 1/R2 + …
R = R1 × R2 × …
R = R1 + R2 + …
A series circuit has three resistors with resistances R1, R2, and R3. Which statement best describes how the circuit’s current and voltage behave?
The same current flows through R1, R2, and R3, while the total voltage equals V1 + V2 + V3.
Different currents flow through R1, R2, and R3, while the total voltage equals the largest of V1, V2, and V3.
The same current flows through all resistors, and the total voltage equals the product V1V2V3.
Different currents flow through each resistor, and the total voltage is zero.
Refer to the series circuit diagram with a single cell and three resistors R1, R2, and R3 in series. Currents I1, I2, and I3 are labeled at three points in the loop. In an ideal series circuit, what is the relationship among these currents?
I1 = I2 = I3
I1 > I2 > I3
I1 < I2 but I2 = I3
I1 = I2 + I3
A series circuit has three resistors R1, R2, and R3 connected to a source Vs. If an ammeter reads 0.40 A at position I2, what are the readings at positions labeled I1 and I3?
I1 = 0.40 A and I3 = 0.40 A
I1 = 0.20 A and I3 = 0.60 A
I1 = 0.40 A and I3 = 0.20 A
I1 = 0.60 A and I3 = 0.60 A
Which statement best explains why I1, I2, and I3 are equal in a series circuit with no branches?
Charge has only one path, so the same amount of charge per second passes every point in the loop
Voltage is the same across all resistors in series, forcing equal currents
Each resistor adds a new branch that divides the current equally
The battery increases current after each component to keep power constant
Refer to the series circuit diagram showing a source Vs and three resistors R1, R2, and R3 with voltage drops V1, V2, and V3 across them. Which statement correctly expresses the relationship among these voltages in a series circuit?
Vs equals V1 + V2 + V3
Vs equals V1 × V2 × V3
Vs equals V1 − V2 − V3
Vs equals (V1 + V2 + V3)/3
In a series circuit with three resistors, what is the correct formula for total resistance?
Rtotal = R1 + R2 + R3
Rtotal = (R1 + R2 + R3)/3
Rtotal = 1/(1/R1 + 1/R2 + 1/R3)
Rtotal = R1 × R2 × R3
A series circuit has Vs = 18 V with three resistors. The voltage drops measured are V1 = 6 V and V2 = 7 V. What is V3? Use the series voltage relationship.
5 V
7 V
11 V
1 V
Three resistors are connected in series: R1 = 120 Ω, R2 = 330 Ω, and R3 = 150 Ω. What is the total resistance of the circuit?
600 Ω
480 Ω
300 Ω
120 Ω
In the series circuit diagram, arrows I1, I2, and I3 are shown at different points in the same loop. Which statement is correct about the current in an ideal series circuit?
I1 = I2 = I3 at all points in the loop
I1 is greater than I2 but less than I3
I1 + I2 + I3 equals the source current
I1 varies only across the largest resistor
A 24 V source is connected to three series resistors with values R1 = 100 Ω, R2 = 200 Ω, and R3 = 200 Ω. Using the total resistance relationship and Ohm’s law, what is the voltage across R1?
4.8 V
6.0 V
8.0 V
12.0 V
Which statement best describes how current behaves in a series circuit when components are added?
Adding components in series reduces the same current everywhere in the loop.
Adding components causes current to vary from point to point in the loop.
Adding components has no effect on current anywhere in the loop.
Adding components makes current higher at one point and lower at another.
Which statement best defines a parallel circuit as shown in the lesson?
A circuit with one continuous loop and a single current path
A circuit that has junctions creating more than one electrical path
A circuit where components are all on the same wire without branches
A circuit in which current stops at each bulb before moving on
According to the "tracing rule", what can you do when analyzing a parallel circuit diagram?
Trace from one side of the battery to the other through every component in a single path
Trace from one side of the battery to the other without lifting your finger, but you cannot pass through all components
Only trace around one branch because other branches are not connected to the battery
Trace only through components that are identical in resistance
In a parallel circuit with three lamps on separate branches, what happens if the top lamp is removed or fails open?
All lamps go out because the circuit is broken everywhere
Only the bottom lamp goes out while the others stay lit
The two bottom lamps remain lit because current still has an alternative path
The battery voltage drops to zero so no lamps work
The cell supplies 6 A entering a junction that splits into three equal branches. What current does each branch carry?
1 A in each branch
2 A in each branch
3 A in each branch
4 A in each branch
Which observation about voltage across components in the given parallel circuit is consistent with the diagrams?
Each lamp in parallel experiences the same battery voltage
Voltage is split equally so each lamp gets half the battery voltage
Only the lamp closest to the battery gets full voltage
Voltage increases in the second branch due to current joining
You are tracing the path of current from the positive terminal in the parallel circuit. What reasoning explains why you cannot pass through all components without lifting your finger?
Because components are disconnected and not part of the circuit
Because branches are in series and must be traversed sequentially
Because the circuit contains multiple paths that diverge at junctions, so a single continuous trace cannot include every branch
Because the battery polarity reverses at each junction blocking current
Refer to the parallel circuit diagram showing three branches with resistors R1, R2, and R3 connected across a source Vs. Which statement correctly describes the number of electrical paths in this circuit?
Exactly one electrical path exists because all components share the same series path.
More than one electrical path exists because components are connected on different branches.
No electrical path exists until a switch is closed in each branch.
There are infinitely many electrical paths because voltage is the same in all branches.
In the depicted parallel network, what is the correct relationship between the total current and the branch currents?
IT = I1 = I2 = I3
IT = I1 + I2 + I3
IT = I1 − I2 − I3
IT = I1 × I2 × I3
Which voltage relationship is shown for the three resistors R1, R2, and R3 connected in parallel across supply Vs?
Vs = V1 + V2 + V3
Vs = V1 = V2 = V3
V1 = Vs − V2 − V3
Vs = V1 × V2 × V3
Which statement about current in a parallel circuit best explains why the total current increases when another branch is added?
Each new branch adds an additional path, so its branch current contributes to IT.
Voltage in the source doubles with each added branch, increasing IT.
R1 forces all current through one branch, reducing IT.
Adding branches decreases all branch currents to zero.
Using Ohm’s law on each branch of the shown parallel circuit, which expression correctly finds the current in branch 2?
I2 = Vs / R2 because the branch voltage equals the supply.
I2 = (V1 + V3) / R2 because currents add in parallel.
I2 = Vs × R2 because voltage and resistance multiply.
I2 = R2 / Vs because resistance divides voltage.
Which identification is correct for the labeled quantities in the first diagram?
V1, V2, V3 are branch currents; IT is branch voltage.
I1, I2, I3 are branch voltages; Vs is total current.
R1, R2, R3 are resistors; I1, I2, I3 are branch currents; Vs is supply voltage.
IT, I1, I2, I3 are resistances in each branch.
A parallel circuit has Vs = 12 V with three resistors R1 = 6 Ω, R2 = 12 Ω, and R3 = 4 Ω as shown. Using the relationships from the diagrams, what is the total current IT?
IT = 1 A
IT = 3 A
IT = 6 A
IT = 9 A
A parallel circuit splits the total current into branch currents. Based on the diagram showing a source feeding three parallel resistors with IT entering and leaving, which statement is correct about voltage across each resistor?
Each resistor has a different voltage depending on its resistance.
All resistors share the same voltage equal to the source voltage.
Only the first resistor has the full source voltage; others get less.
Voltage is zero across each branch because current splits.
Using the parallel resistance relationship 1/RT = 1/R1 + 1/R2 + 1/R3, what happens to the total resistance RT when an additional parallel branch is added? Assume the added branch has a finite resistance.
RT increases because more components are added.
RT stays the same because voltage is the same in all branches.
RT decreases because the sum of reciprocals increases.
RT becomes the average of all branch resistances.
Two resistors, 6 Ω and 3 Ω, are connected in parallel. Using the formula for parallel resistance, what is the total resistance RT?
2 Ω
9 Ω
4.5 Ω
1 Ω
Which statement best describes a key disadvantage of a series circuit?
If one component fails, the entire circuit stops working.
Each component receives the full source voltage independently.
Adding more bulbs makes each bulb brighter due to higher current.
Current splits across branches, reducing the impact of a failure.
In a series string of identical bulbs connected to a fixed-voltage source, what happens to the brightness of each bulb as more identical bulbs are added?
Each bulb becomes dimmer because the source voltage is divided among more bulbs.
Each bulb becomes brighter because total resistance decreases.
Brightness stays the same because each bulb gets the full source voltage.
Some bulbs brighten while others dim because current is different at each point.
A set of three identical bulbs is wired in series to a battery. One bulb burns out and creates an open circuit. Predict what you observe and choose the best explanation.
All bulbs go out because the open circuit stops the same current that must pass through each bulb.
Only the failed bulb goes out because the remaining bulbs still receive the full battery voltage through alternate paths.
The remaining bulbs get brighter because the battery’s voltage is now shared by fewer bulbs while current increases in the open section.
Two bulbs stay on but dimmer because current splits between the working bulbs.
According to the statement: "If more resistors are connected in parallel the total resistance will always decrease," which explanation best describes why this happens?
Each added branch provides an additional path for current, reducing overall opposition to flow.
The voltage source automatically increases its voltage to keep current constant.
Parallel connections force all current through a single resistor, lowering resistance.
Adding resistors in parallel increases the length of the circuit, which lowers resistance.
A circuit has two identical resistors in parallel. If a third identical resistor is added in parallel, what happens to the total resistance of the circuit?
It decreases because more branches allow current to split among additional paths.
It stays the same because identical resistors cancel each other out in parallel.
It increases because adding components always adds resistance.
It alternately increases and decreases depending on which branch is used first.
In a parallel circuit, what happens if one bulb fails?
All bulbs turn off because the circuit is broken
Only the failed bulb stops; the rest continue to work
Brightness of all remaining bulbs decreases drastically
Voltage across the whole circuit drops to near zero
Which statement best explains why adding more components in parallel changes the overall resistance of the circuit?
Adding parallel branches provides more paths for current, reducing total resistance
Adding parallel branches removes resistors, increasing total resistance
Adding parallel branches forces all current through one path, keeping resistance constant
Adding parallel branches increases the length of the circuit, which raises resistance
A household uses a 12 V supply. Three identical bulbs are connected in parallel. What is the voltage across each bulb?
12 V across each bulb
4 V across each bulb
Variable voltage depending on branch position
0 V across each bulb unless one fails
Consider two circuits built from identical bulbs: Circuit A has one bulb; Circuit B has two bulbs in parallel. Which comparison aligns with the advantages of parallel circuits?
Bulbs in Circuit B are dimmer because voltage is shared between branches
Bulbs in Circuit B are as bright as the single bulb in Circuit A because each branch gets the full supply voltage
Bulbs in Circuit B are brighter because resistance increases with more components
Bulbs in Circuit B only work if both bulbs are functioning
A series circuit has a 6 V supply and two identical 10 Ω resistors in series. What is the voltage across each resistor, V1 and V2?
V1 = 6 V, V2 = 0 V
V1 = 3 V, V2 = 3 V
V1 = 4 V, V2 = 2 V
V1 = 2 V, V2 = 4 V
In a series circuit with two 10 Ω resistors connected to a 10 V supply, how will the supply voltage divide across the resistors?
Each resistor gets 10 V because they are identical.
One resistor gets 7 V and the other 3 V due to order in the loop.
Each resistor gets 5 V because the total splits equally in series.
The first resistor gets 6 V and the second 4 V because of current drop.
In a series circuit with a total voltage of 12 V and two resistors, R1 = 4 Ω and R2 = 8 Ω, what is the voltage drop across R2?
6 V
12 V
8 V
4 V
What happens to the total current in a series circuit if an additional resistor is added?
The total current becomes zero
The total current remains the same
The total current decreases
The total current increases
In a series circuit with three resistors, if the total resistance is 30 Ω and the current is 2 A, what is the total voltage supplied by the battery?
15 V
30 V
10 V
60 V
In a circuit with a 12 V battery and two resistors R1 = 4 Ω and R2 = 8 Ω connected in series, what is the voltage drop across R2?
4 V
8 V
12 V
6 V
For three resistors R1 = 10 Ω, R2 = 20 Ω, and R3 = 30 Ω connected in parallel, what is the total resistance?
1/60 Ω
5 Ω
10 Ω
60 Ω
In a series circuit with a 9 V battery and three resistors R1, R2, and R3, if the voltage across R1 is 3 V and across R2 is 4 V, what is the voltage across R3?
4 V
5 V
3 V
2 V
What is this the symbol for?
(a)
What is this the symbol for?
(a)
What is this the symbol for?
(a)
What is this the symbol for?
(a)
What is this the symbol for?
(a)
What is this the symbol for?
(a)
What is this the symbol for?
(a)
Which is the symbol for a variable resistor?
To measure the voltage and current correctly in this circuit
The yellow must be the ammeter and the blue must be the voltmeter
The yellow must be the voltmeter and the blue must be the ammeter
The yellow must be the ammeter and the blue must be the ammeter
The yellow must be the voltmeter and the blue must be the voltmeter
Electrons flow in the same direction as the current.
True
False
What is this the symbol for?
(a)
If lamp 1 is unscrewed from its holder, what will happen to lamp 2?
It will get brighter
It will stay the same brightness
It will go out
Nothing will happen
If lamp 2 is unscrewed from its holder, what will happen to lamp1?
It will stay lit
It will go out
It will get dimmer
It will dissapear
What is the total resistance of two resistors, 4 Ω and 12 Ω, connected in series?
16 Ω
8 Ω
48 Ω
3 Ω
In a parallel circuit with three resistors of 2 Ω, 4 Ω, and 6 Ω, what is the equivalent resistance?
12 Ω
2 Ω
1 Ω
3 Ω
In a circuit with a 12 V battery and two resistors in series, if the voltage drop across the first resistor is 5 V, what is the voltage drop across the second resistor?
12 V
0 V
5 V
7 V
