Ohms Law

Front

What is Ohm's Law?

Back

Ohm's Law states that the current (I) through a conductor between two points is directly proportional to the voltage (V) across the two points and inversely proportional to the resistance (R) of the conductor. It can be expressed as V = I × R.

Front

What is the formula to calculate resistance using Ohm's Law?

Back

Resistance (R) can be calculated using the formula R = V / I, where V is the voltage and I is the current.

Front

If a bulb draws 0.5 A from a 120 V supply, what is the resistance?

Back

R = V / I = 120 V / 0.5 A = 240 Ω.

Front

How do you calculate power in an electrical circuit?

Back

Power (P) can be calculated using the formula P = V × I, where V is the voltage and I is the current.

Front

What is the power delivered to a motor if a 7.5 V battery delivers 1.5 A?

Back

P = V × I = 7.5 V × 1.5 A = 11.25 W.

Front

What is the resistance of a bulb that draws 0.6 A from a 150 V supply?

Back

R = V / I = 150 V / 0.6 A = 250 Ω.

Front

If a bulb draws 0.4 A from a 90 V supply, what is the resistance?

Back

R = V / I = 90 V / 0.4 A = 225 Ω.

Front

What is the voltage across a resistor if a current of 2 A flows through a 15 Ω resistor?

Back

V = I × R = 2 A × 15 Ω = 30 V.

Front

What does it mean if a circuit has high resistance?

Back

High resistance means that the circuit restricts the flow of current, resulting in lower current for a given voltage.

Front

What does it mean if a circuit has low resistance?

Back

Low resistance means that the circuit allows more current to flow for a given voltage.