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Basic Electrical Circuits and Components Worksheet

Total questions: 48

Worksheet time: 24mins

Name
Class
Date
1.

In a series circuit, if one bulb burns out, what happens to the rest of the circuit?

a)

They all go out

b)

They get brighter

c)

They stay the same

d)

The current reverses

2.

In a parallel circuit, the voltage across each branch is:

a)

Different on each

b)

Equal to source voltage

c)

Half of source voltage

d)

Zero

3.

Which of these will reduce current flow in a series circuit?

a)

Adding resistance

b)

Adding another parallel branch

c)

Shorting a component

d)

Increasing voltage

4.

If a circuit draws 5 amps and has a 2 Ω resistance, what is the voltage?

a)

2.5 V

b)

7 V

c)

10 V

d)

12 V

5.

Which statement about voltage drop is true?

a)

Voltage increases through a resistor

b)

Voltage stays constant through all components

c)

Voltage is used as current flows through resistance

d)

Voltage only drops in parallel circuits

6.

A complete circuit must include:

a)

Power source, load, and path

b)

Fuse and relay only

c)

Battery and ground

d)

Switch only

7.

A fuse protects a circuit by:

a)

Increasing resistance

b)

Opening the circuit if current is too high

c)

Allowing more voltage through

d)

Regulating amperage

8.

What is the function of a relay?

a)

Store electrical energy

b)

Convert AC to DC

c)

Use a small current to control a large one

d)

Act as a resistor

9.

Which tool measures voltage drop across a component?

a)

Test light

b)

DVOM in DC volts mode

c)

Ammeter

d)

Ohmmeter

10.

A bad ground connection can cause which symptom?

a)

Higher battery voltage

b)

Dim lights or slow motors

c)

Blown fuses

d)

Alternator overcharge

11.

A switch is used to:

a)

Step up voltage

b)

Break or complete the circuit path

c)

Regulate amperage

d)

Act as a resistor

12.

A resistor is often used to:

a)

Increase current flow

b)

Protect against short circuits

c)

Control voltage and current in a circuit

d)

Open the circuit when hot

13.

Ohm’s Law states the relationship between:

a)

Power, voltage, current

b)

Voltage, current, resistance

c)

Voltage, amps, watts

d)

Power, energy, resistance

14.

If voltage increases and resistance stays the same, current will:

a)

Increase

b)

Decrease

c)

Stay the same

d)

Stop completely

15.

What happens to current if resistance doubles and voltage stays constant?

a)

Doubles

b)

Cuts in half

c)

Triples

d)

Stays equal

16.

Using Ohm’s Law, calculate resistance if V = 12 V and I = 3 A.

a)

2 Ω

b)

3 Ω

c)

4 Ω

d)

6 Ω

17.

The unit for resistance is:

a)

Volt

b)

Amp

c)

Ohm

d)

Watt

18.

What is the current in a 12 V circuit with 24 Ω of resistance?

a)

0.25 A

b)

0.5 A

c)

1 A

d)

2 A

19.

A headlight circuit has 3 A of current and 4 Ω of resistance. What is the voltage drop across it?

a)

7 V

b)

10 V

c)

12 V

d)

15 V

20.

The path that current flows through from the power source to the load and back is called a:

a)

Parallel branch

b)

Circuit

c)

Resistor

d)

Diode

21.

In a short circuit, current flows:

a)

Through the load as normal

b)

Through the fuse first

c)

Along an unintended low-resistance path

d)

Only when the switch is off

22.

When resistance in a circuit increases, what happens to current flow?

a)

Increases

b)

Decreases

c)

Stays constant

d)

Doubles

23.

The amount of work done by electrical energy is measured in:

a)

Ohms

b)

Watts

c)

Volts

d)

Amps

24.

A series circuit always has:

a)

Equal resistance across each component

b)

Only one path for current to flow

c)

Different voltage in each branch

d)

A fuse in every branch

25.

In a parallel circuit, if one branch opens:

a)

The entire circuit fails

b)

Only that branch stops working

c)

Current reverses direction

d)

Voltage drops to zero everywhere

26.

The total resistance in a parallel circuit is always:

a)

Greater than the highest resistor

b)

Equal to the average resistor value

c)

Less than the smallest resistor

d)

The sum of all resistors

27.

A voltage drop test helps technicians find:

a)

Open circuits

b)

Short circuits

c)

High-resistance connections

d)

Parasitic draws

28.

The symbol for a resistor on a wiring diagram looks like a:

a)

Zig-zag line

b)

Circle with a plus sign

c)

Triangle and line

d)

Straight line

29.

A diode allows current to flow:

a)

Both directions equally

b)

Only in one direction

c)

Only when voltage is zero

d)

In alternating pulses

30.

Which component stores energy and smooths voltage spikes?

a)

Capacitor

b)

Fuse

c)

Coil

d)

Transistor

31.

The coil inside a relay functions as:

a)

A permanent magnet

b)

An electromagnet that pulls contacts closed

c)

A resistor to reduce current flow

d)

A fuse link

32.

Which device converts mechanical energy to electrical energy?

a)

Battery

b)

Alternator

c)

Starter motor

d)

Ignition coil

33.

A poor connection at a connector will usually cause:

a)

More current flow

b)

Less current and heat buildup

c)

A total short circuit

d)

Voltage increase

34.

The load in an electrical circuit is the part that:

a)

Generates current

b)

Consumes electrical energy

c)

Stores voltage

d)

Grounds the system

35.

Which component is used to control current flow automatically when temperature changes?

a)

Thermistor

b)

Diode

c)

Capacitor

d)

Resistor

36.

What happens if a fuse with too high a rating is installed?

a)

It will blow too soon

b)

It might allow wiring damage before blowing

c)

It prevents all voltage drop

d)

It lowers current flow

37.

What is the current in a 9-volt circuit with 3 ohms of resistance?

a)

1 A

b)

2 A

c)

3 A

d)

9 A

38.

Which of the following is the correct formula for Ohm’s Law?

a)

I = V × R

b)

V = I × R

c)

R = V × P

d)

P = I / R

39.

A circuit has 6 volts and 2 amps of current. What is the resistance?

a)

2 Ω

b)

3 Ω

c)

6 Ω

d)

12 Ω

40.

When testing a fuse for continuity, the DVOM should read:

a)

Infinite resistance (OL)

b)

Zero or very low ohms

c)

12 volts

d)

Negative current

41.

When using a DVOM set to ohms, the circuit should be:

a)

Powered on

b)

Powered off

c)

Grounded

d)

Tested under load

42.

If a 10-amp fuse keeps blowing, the circuit likely has:

a)

An open

b)

Excess resistance

c)

A short to ground

d)

Low voltage

43.

Power in an electrical circuit is measured in:

a)

Ohms

b)

Volts

c)

Watts

d)

Amps

44.

Which situation describes an open circuit?

a)

A wire insulation rubbed through

b)

A blown fuse or disconnected wire

c)

A relay stuck closed

d)

Corrosion at a connector causing partial contact

45.

What would happen to current if voltage is cut in half and resistance stays the same?

a)

Current doubles

b)

Current halves

c)

Current stays constant

d)

Current stops completely

46.

A voltage reading of 0 volts on both sides of a load indicates:

a)

Open circuit

b)

Short to ground before the load

c)

Short to power

d)

High resistance after the load

47.

Which of these is not part of a complete circuit?

a)

Load

b)

Source

c)

Switch

d)

Insulator

48.

When measuring current, the meter must be connected:

a)

In parallel with the load

b)

In series with the load

c)

Across the power and ground

d)

Between fuse and relay