SP10d-SP10e test

Question 1

What unit is resistance measured in?

Answer 1

ohms

Question 2

How does connecting two resistors in series affect resistance?

Answer 2

The total resistance of the circuit is increased because the pathway becomes harder for current to flow through

Question 3

How is potential difference from a cell shared between two resistors?

Answer 3

Not equally, they will be a greater potential difference across the resistor with greater resistances

Question 4

How does connecting two resistors in parallel affect resistance?

Answer 4

When two resistors are connected in parallel the total resistance of the circuit is less than the resistance of the individual resistors

This is because there are now more paths for the current

Question 5

Describe the graph of current against potential difference for a fixed resistor.

Answer 5

the graph forms a straight line through the origin which shows that the two values are in direct proportion.

as potential difference changes, current also changes by the same percentage

Question 6

Describe the graph of current against potential difference for a filament lamp.

Answer 6

in the start potential difference increases with current linearly however as it get hotter resistance increases which means when potential difference changes , current doesn’t change by the same percentage (non-linearly)

Question 7

Describe the graph of current against potential difference for a diode.

Answer 7

on one side of the graph the line is flat representing an ‘infinite’ resistance but in the other direction the resistance is very low. this means current can only flow in one direction through the diode

Question 8

Describe how the resistance of an LDR changes with increasing light intenisty

Answer 8

as light intensity increases - resistance decreases