Ohm's Law

Question 1

What causes Resistance?

Answer 1

• The flow of electrons which make up the current in the circuit, collide with vibrating ions/atoms inside the wire
• The more collisions as they pass through the wire, the more resistance to the movement of these electrons is experienced. SO A GREATER RESISTANCE

Question 2

What is the Ohm’s Law equation?

Answer 2

Question 3

How many volts of potential difference are needed to drive 6 amperes of current through a resister of 60 ohm’s?

Answer 3

V=? I=6 R=60
V = 60 × 6
V = 360v

Question 4

What P.D. (Potential Difference) is needed to drive a current of 2A through a 5Ω resistor?

Answer 4

V=? I=2 R=5
V = 2 × 5
V = 10v

Question 5

What is the resistance of a light bulb which needs 6 volts and 0.06 amperes to light it?

Answer 5

V=6 I=0.06 R=?
R = 6 / 0.06
R = 100Ω

Question 6

A P.D. (Potential Difference) of 6v is applied across a 2Ω resistor. What current flows?

Answer 6

V=6 I=? R=2
I = 6 / 2
I = 3A

Question 7

What is the value of a resistance if 20v drives 2A through it?

Answer 7

V=20 I=2 R=?
R = 20 / 2
R = 10Ω

Question 8

What is the current flowing through a resistor of 960 Ohm’s, When a Potential Difference of 120 volts applied?

Answer 8

V=120 I=? R=960
I = 120 / 960
I = 0.125A

Question 9

‘Mains’ voltage is 240v. What current will flow through a one bar electric fire which has a resistance of 60 Ohms?

Answer 9

V=240 I=? R=60
I = 240 / 60
I = 4A