Question 3
Current into junction must equal current exiting junction.
Look for a junction where I1 and I2 enter it whilst I3 and I4 exit it.
Question 10
The TOTAL current across the two must add up to 9V. The potential drop across the resistor and lamp respecticvely must be either :
9 and 0
8 and 1
7 and 2
6 and 3
And there are more combintions.
Determine the current of both the resistor and lamp at the given voltages and add the curents up to see if they match any of the options.
Question 14
Ignore the fact that this about oil and water coatings and simply write the same points you would have written if you had simply been asked what is the reason for an interference pattern forming.
