Questions on Electricity and Circuits

Give yourself 30 minutes to answer the questions below. Try your best not to use your notes first time round then go through the questions again and use your notes and the internet but answer in a different colour pen so you can see the information you did not know. Then go through the questions using the mark scheme at the end of the paper, add any answers you’ve missed in another colour.

Q1.
 
The nucleus of an atom contains
(1)
   A    only electrons
   B    only neutrons
   C    electrons and neutrons
   D    protons and neutrons

Q2.
 
Which of these symbols is used to represent a thermistor in an electrical circuit?
(1)

Q3.

 Explain why the temperature of a resistor increases when a current passes through it.
(2)
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
Q4.
 
An electric heater is connected to a 230 V supply.
The power supplied to the heater is 2.6 kW.
Calculate the current in the heater.
(3)

current = ........................................................... A
Q5.
 
A wire in a circuit carries a current of 0.9 A. 
Calculate the quantity of charge that flows through the wire in 50 s.
State the unit of charge with your answer.
Use the equation
charge = current × time
(3)

quantity of charge = ................................ unit ........................... 
Q6.
 
A student sets up an experiment to measure the potential difference (voltage) across a filament lamp.
She changes the current through the lamp.
The diagram shows the circuit she used.

(c) Calculate the resistance of the lamp when the current is 0.44 A and the potential difference is 10.0 V.
(2)

 resistance = ......................Ω
Q7.
 
Figure 10 shows two electrical devices for heating water.

(i)  The current in the element of the immersion heater is 14 A.
The power of the immersion heater is 130 W.
Calculate the resistance of the immersion heater.
Give your answer to two significant figures.
(3)

resistance of immersion heater = ........................................................... Ω
(ii)  The current in the heating element of the kettle is 8.3 A.
State two differences between the movement of charge in the heating 
element of the kettle and the movement of charge in the immersion heater.
(2)
1 .......................................................................................................................................... 
 ............................................................................................................................................. 
2 .......................................................................................................................................... 
 ............................................................................................................................................. 
 
Q8.
 
Figure 7 shows a circuit used to light a lamp.

Figure 7
(i)  State two things you could do to the circuit to make the lamp dimmer.
(2)
1 .......................................................................................................................................... 
 ............................................................................................................................................. 
2 .......................................................................................................................................... 
 ............................................................................................................................................. 
(ii)  The energy transferred by the lamp in 20 s is 18 J.
Calculate the power of the lamp.
State the unit.
(4)

power of the lamp = ........................................................... 
unit = ........................................................... 
(iii)  The potential difference across the lamp is 4.2 V.
The current in the lamp is then 0.19 A.
Calculate the resistance of the lamp.
(3)

resistance of the lamp = ........................................................... Ω
 
Q9.
 
The graphs show how the current in a component changes with the voltage applied across the component.
Draw a line from each component to its correct graph.
(2)

Mark Scheme

Q1.

 

Q2.

 

Q3.

  	Answer	Acceptable answers	Mark	
  	An explanation linking: electrons 
 (1)  colliding with / bumping into ions in the lattice /atoms in the metal (1)   	  colliding with other electrons If no other marks scored, allow for 1 mark for "electrical energy transferred/changed into thermal/heat energy"  do not allow energy being created or produced   	(2) 	

Q4.

 

Q5.

 

Q6.

  	Answer	Acceptable answers	Mark	
  	substitution (1)
 10/0.44 or 250/11 evaluation (1)
 23 (ohms) 	give full marks for correct
 answer, no working 22.7(ohms),22.73 (ohms),
 22.72(ohms)
 Ignore excessive decimal places. 	(2)	

Q7.

 

Q8.

 

Q9.