5) Ohm’s Law (p. 14) & Series and parallel circuits (p.15)

What is the formula of Ohm’s Law?

• V = I x R
• R = I x V
• I = V + R
• V = I / R

Answer explanation

V = I x R is correct because Ohm's Law defines voltage as current times resistance.

What happens to the current if you double the voltage?

• It is halved
• It stays the same
• It doubles
• It becomes zero

Answer explanation

It doubles is correct because For a constant resistance, voltage and current are directly proportional.

What is the resistance if V = 4.5V and I = 0.5A?

• 9Ω
• 2.25Ω
• 4Ω
• 1.5Ω

Answer explanation

9Ω is correct because Using R = V/I → R = 4.5 / 0.5 = 9Ω.

What unit do we use for resistance?

• Volt
• Ampere
• Watt
• Ohm

Answer explanation

Ohm is correct because Resistance is measured in ohms (Ω).

How many paths are there in a parallel circuit?

• One
• Two
• More than one
• None

Answer explanation

More than one is correct because Each branch has its own current path.

What is the current if V = 3V and R = 1.5Ω?

• 1A
• 2A
• 0.5A
• 3A

Answer explanation

2A is correct because Using I = V / R → I = 3 / 1.5 = 2A.

Which circuit keeps all bulbs on if one fails?

• Series
• Parallel
• Open
• None

Answer explanation

Parallel is correct because In parallel, other paths keep functioning.

Which component limits the current in a circuit?

• Battery
• Switch
• Resistor
• Wire

Answer explanation

Resistor is correct because Resistors control the current flow.

What is the total resistance in a series circuit?

• Sum of all resistors
• Same as one
• Zero
• Average of all

Answer explanation

Sum of all resistors is correct because In series: R = R1 + R2 + R3

What does a voltmeter measure?

• Current
• Resistance
• Voltage
• Power

Answer explanation

Voltage is correct because A voltmeter measures potential difference.