Circuit Diagram Examples in Physics

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Circuit Diagram.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Physics.

Concept Recap

A simplified drawing of an electrical circuit using standardized symbols for components like batteries, resistors, switches, and bulbs.

A circuit diagram is like a map for electricity — it shows what's connected to what without drawing realistic pictures.

Read the full concept explanation →

How to Use These Examples

  • Read the first worked example with the solution open so the structure is clear.
  • Try the practice problems before revealing each solution.
  • Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: Circuit Diagram asks students to follow the circuit path and identify what quantity changes at each component.

Common stuck point: Students often know a formula related to circuit diagram but skip the recognition step: Can I identify the circuit path, what quantity is flowing or changing, and which electrical rule links the quantities? That leads to a correct-looking substitution attached to the wrong physical model.

Sense of Study hint: Ask: Can I identify the circuit path, what quantity is flowing or changing, and which electrical rule links the quantities?

Worked Examples

Example 1

easy
A circuit diagram shows a 6 V6 \text{ V} battery connected to a 2 Ω2 \text{ } \Omega resistor with an ammeter in series. What reading does the ammeter show?

Answer

I=3 AI = 3 \text{ A}

First step

1
An ammeter is connected in series to measure current through a component.

Full solution

  1. 2
    The ammeter has negligible resistance, so it does not significantly affect the circuit.
  2. 3
    Current: I=VR=62=3 AI = \frac{V}{R} = \frac{6}{2} = 3 \text{ A}
Circuit diagrams use standard symbols for components. An ammeter (circle with 'A') is always placed in series with the component whose current you want to measure, since current must flow through it.

Example 2

medium
A circuit diagram shows a 10 V10 \text{ V} battery, a 5 Ω5 \text{ } \Omega resistor, and a voltmeter connected in parallel across the resistor. The circuit also has a 2 A2 \text{ A} current. What does the voltmeter read? Is the voltmeter connection correct?

Example 3

medium
A schematic shows a 12 V12\text{ V} battery in series with two resistors R1=4 ΩR_1 = 4\,\Omega and R2=2 ΩR_2 = 2\,\Omega. What current flows?

Example 4

medium
A schematic shows a 10 V10\text{ V} battery in series with R1=2 ΩR_1 = 2\,\Omega and then a parallel pair R2=6 ΩR_2 = 6\,\Omega and R3=3 ΩR_3 = 3\,\Omega. Find the total current from the battery.

Example 5

hard
A schematic shows three resistors: R1=6 ΩR_1 = 6\,\Omega and R2=3 ΩR_2 = 3\,\Omega in parallel, in series with R3=2 ΩR_3 = 2\,\Omega, across a 10 V10\text{ V} battery. Find the voltage across R2R_2.

Example 6

challenge
A schematic shows a 12 V12\text{ V} battery with internal resistance 1 Ω1\,\Omega powering a 5 Ω5\,\Omega external resistor. Find the terminal voltage of the battery.

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

medium
A circuit diagram shows three resistors: R1=2 ΩR_1 = 2 \text{ } \Omega in series with a parallel combination of R2=6 ΩR_2 = 6 \text{ } \Omega and R3=3 ΩR_3 = 3 \text{ } \Omega. A 12 V12 \text{ V} battery powers the circuit. What is the total current?

Example 2

hard
A circuit diagram shows a 12 V12 \text{ V} battery connected to: R1=4 ΩR_1 = 4 \text{ } \Omega in series with two parallel branches — one with R2=6 ΩR_2 = 6 \text{ } \Omega and the other with R3=3 ΩR_3 = 3 \text{ } \Omega in series with R4=3 ΩR_4 = 3 \text{ } \Omega. Find the total current and the current through R2R_2.

Example 3

easy
What does the symbol of two parallel lines of unequal length represent?

Example 4

easy
Does a circuit diagram show the true physical layout of the wires?

Example 5

easy
In a diagram, two components share one path with no branch between them. Are they in series or parallel?

Example 6

easy
What does a simple resistor symbol (zigzag or rectangle) represent?

Example 7

easy
In a diagram, components connect across the same two nodes via separate branches. Series or parallel?

Example 8

easy
On a battery symbol, which terminal is the longer line?

Example 9

easy
What does an open gap with a hinged line in a diagram usually represent?

Example 10

easy
Two equal-length parallel lines in a diagram represent which component?

Example 11

medium
A diagram shows a battery, then the wire splits into two resistors that rejoin before returning. Are the resistors in series or parallel?

Example 12

medium
A schematic shows a 66 V battery and a single resistor in a loop, drawn as a square. How many distinct current paths are there?

Example 13

medium
In a diagram, the layout draws a resistor far from the battery with a long bent wire. Does the bend affect the circuit's behavior?

Example 14

medium
A diagram shows two switches both in the single main path. For current to flow, must both be closed or just one?

Example 15

medium
A diagram has two switches in parallel branches feeding one bulb. How many must be closed for the bulb to light?

Example 16

medium
In a schematic, a resistor and a bulb are between the same two nodes as separate branches. If the bulb's branch breaks, does current still flow through the resistor?

Example 17

medium
A diagram shows a battery with a resistor whose symbol has an arrow through it. What kind of component is this?

Example 18

challenge
A schematic shows a battery, then the path splits: branch A has two resistors one after another, branch B has one resistor, and the branches rejoin. Describe the topology of branch A's resistors and the two branches.

Example 19

challenge
A diagram shows a battery and three bulbs: one in the main line before the path splits into two parallel bulbs. If the main-line bulb burns out, what happens to the two parallel bulbs?

Example 20

challenge
A schematic uses an ammeter and a voltmeter. The ammeter must be placed in series with the component, the voltmeter in parallel. Why these placements?

Example 21

medium
In a diagram, a single resistor sits between the battery's two terminals with no branches. Series or parallel topology?

Example 22

medium
A diagram shows an arrow pointing at a circle with a cross (a meter) placed in the main current path. Is this an ammeter or voltmeter, by placement?

Example 23

easy
A schematic shows a 9 V9\text{ V} battery connected to a 3 Ω3\,\Omega resistor and an ammeter in series. What does the ammeter read?

Example 24

easy
On a schematic, a single line segment between two components represents what?

Example 25

easy
A schematic shows two batteries with their long lines pointing the same direction in a single loop. What total EMF appears in the loop?

Example 26

easy
On a schematic, a circle with a letter 'A' inside represents what?

Example 27

medium
A diagram shows a 6 V6\text{ V} battery connected to two parallel resistors 4 Ω4\,\Omega and 12 Ω12\,\Omega. Find the current from the battery.

Example 28

medium
In a schematic, two bulbs in series are powered by a 12 V12\text{ V} battery. If they are identical, what voltage drops across each?

Example 29

medium
A diagram shows a 9 V9\text{ V} battery and three bulbs in parallel. If each bulb has resistance 9 Ω9\,\Omega, find the current through one bulb.

Example 30

medium
A schematic has a switch in series with the battery, then the path splits into two parallel bulbs. What happens to both bulbs when the switch opens?

Example 31

medium
A diagram shows two switches each in its own parallel branch, each branch with its own bulb. If switch 1 opens, what happens to the bulb in branch 2?

Example 32

medium
A schematic shows two resistors R1=2 ΩR_1=2\,\Omega and R2=3 ΩR_2=3\,\Omega in series across a battery; an ammeter is placed in series and reads 2 A2\text{ A}. What is the battery EMF?

Example 33

medium
In a schematic, a wire crosses another with a small bump (or labeled 'no connection'). What does the bump mean?

Example 34

hard
A schematic shows a 24 V24\text{ V} battery connected to a series resistor R1=4 ΩR_1 = 4\,\Omega then a parallel block of R2=6 ΩR_2 = 6\,\Omega and R3=12 ΩR_3 = 12\,\Omega. Find the current through R3R_3.

Example 35

hard
A schematic shows three identical bulbs RR each: one in series with a parallel pair of the other two, driven by EMF VV. Find the power dissipated by the series bulb relative to one parallel bulb.

Example 36

hard
A schematic shows a 12 V12\text{ V} battery, a switch, and two bulbs in series. The switch is initially open. If the user closes the switch, what happens to the voltage measured across the open switch (before vs after)?

Example 37

hard
A schematic shows two bulbs labeled '60 W,120 V60\text{ W}, 120\text{ V}' connected in series across 120 V120\text{ V}. How brightly does each bulb glow compared to its rated brightness?

Example 38

hard
A schematic shows two bulbs of resistances R1=5 ΩR_1 = 5\,\Omega and R2=10 ΩR_2 = 10\,\Omega in series across a 15 V15\text{ V} battery. Which bulb is brighter?

Example 39

challenge
A schematic shows a Wheatstone bridge: four RR in a diamond with a galvanometer across the middle, balanced. If one RR is replaced with 2R2R, what current direction flows through the galvanometer (relative to the labeled top vertex A)?
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Background Knowledge

These ideas may be useful before you work through the harder examples.

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