Paper 1 Current Electricity Fundamentals Answers

Q	Ans	Brief reason
1	B	$I=\Delta Q/\Delta t$.
2	B	$Q=It=10\mathrm{C}$.
3	A	$V=W/Q$.
4	B	Definition of resistance.
5	A	Ohm law condition.
6	B	Electrons drift opposite conventional current.
7	A	Resistivity formula.
8	A	$R\propto L$.
9	B	$R\propto 1/A$.
10	B	Emf is source energy supply per unit charge.
11	B	Terminal p.d. is emf minus lost volts.
12	B	Lost volts $=Ir$ across internal resistance.
13	A	Electrical power relation.
14	B	$P=I^{2}R=24\mathrm{W}$.
15	B	$J=I/A$.
16	A	Drift relation.
17	A	Heating changes resistance.
18	B	For $V$ vs $I$, gradient is $R$.
19	A	From $R=\rho L/A$.
20	B	$V=\mathcal{E}-Ir$ has gradient $-r$.