P2 : Resistance and Ohm's Law

Question 1

Resistance

Answer 1

A measure of how hard it is for the current to pass through a component in a circuit
Higher resistance of a component the harder it is for the current to pass through that component

Question 2

What causes resistance

Answer 2

When electrons collide with atoms / ions in a metal

Question 3

Factors affecting resistance

Answer 3

The thinner the wire, the greater resistance as there’s higher chance of collision
If the wire is hotter then the atoms vibrate faster and further and so again there is a higher chance of a collision causing resistance to increase

Question 4

Ohm’s law

Answer 4

Ohm’s law states that the current through a resistor is Directly proportional to the potential difference provided that temperature is constant

Question 5

What is the equation that links potential difference, current, resistance

Answer 5

V = I x R
V = Potential difference measured in volts
I = Current measured in amps
R = Resistance measured in ohms

Question 6

Ohmic

Answer 6

If an electric component has a I-V graph that is a a straight line (directly proportional) we say that component is ohmic.

Question 7

Resistance in a series circuit

Answer 7

Resistances add together in a series circuit
Rtot = R1 + R2 . In parallel, resistance decreases