current, resistance and voltage

Question 1

What is Ohm’s Law?

Answer 1

Voltage (V) = Current (I) × Resistance (R)

Question 2

A resistor has a resistance of 5 Ω, and a current of 2 A flows through it. What is the voltage across it?

Answer 2

V = 2 × 5 = 10 V

Question 3

How does increasing resistance affect current in a circuit?

Answer 3

Higher resistance decreases current if voltage remains the same.

Question 4

What is the equation for charge flow?

Answer 4

Charge (Q) = Current (I) × Time (t)

Question 5

A current of 3 A flows for 5 seconds. How much charge passes?

Answer 5

Q = 3 × 5 = 15 C

Question 6

How does current vary with voltage for a resistor?

Answer 6

Current increases proportionally with voltage (Ohm’s Law applies).

Question 7

How does current vary with voltage for a filament lamp?

Answer 7

As voltage increases, resistance increases, so current increases at a decreasing rate.

It means the current is still increasing, but more slowly over time.

Question 8

How does current behave in a diode?

Answer 8

A diode only allows current to flow in one direction.

Question 9

What is the effect of light intensity on an LDR’s resistance?

Answer 9

Higher light intensity → Lower resistance

Question 10

How does temperature affect a thermistor’s resistance?

Answer 10

Higher temperature → Lower resistance