20 questions · 142 marks · ≈ 2 hours
Fig. 10.1 shows the apparatus for an experiment on electrostatics.
Identify the pieces of equipment that are electrical conductors and those that are electrical insulators. Draw a line from each piece of equipment to the correct box.
State and explain how the polythene strip can be given a negative charge.
Describe how the apparatus in Fig.10.1 could be used to demonstrate that the polythene strip has a negative charge.
A student sets up an electrical circuit. She draws part of the circuit diagram, as shown in Fig.8.1.
On Fig.8.1, draw the circuit symbols for three devices so that the student can:
(i) measure the total current in the circuit
(1 mark)
(ii) vary the current in the lamp B only
(1 mark)
(iii) measure the potential difference (p.d.) across lamp B.
(2 marks)
Extract:
A student sets up an electrical circuit. She draws part of the circuit diagram, as shown in Fig.8.1.
The current in lamp A is 0.20 A. The potential difference (p.d.) across lamp A is 6.0 V.
Calculate the resistance of lamp A.
resistance = ......................................................Ω
Fig. 10.1 shows a balloon hanging from an insulating thread.
(i) A student gives the balloon a positive charge.
Which statement explains why the balloon becomes positively charged? Tick one box.
square The balloon gains electrons
square The balloon loses electrons
square The balloon gains protons
square The balloon loses protons
(1 mark)
(ii) The student brings a charged rod close to the balloon as shown in Fig. 10.2.
State the type of charge on the rod. Explain your answer.
(2 marks)
Electrical charges can move easily through some materials.
Draw a circle around each material that charges can move through easily.
| copper | plastic | rubber | silver | wood |
|---|
A student rubs a plastic rod with a dry cloth, as shown in Fig. 8.1. The rod becomes negatively charged.
(i) Use words from the box to complete the sentence.
| air | cloth | electrons | hand | neutrons | protons |
|---|
The rod becomes negatively charged because ......................................... move from the ......................................... to the rod.
(2 marks)
(ii) The student moves the rod close to a suspended, charged rod. The two rods repel each other.
State the type of charge on the suspended rod.
(1 mark)
(iii) Explain your answer to (a)(ii).
(1 mark)
A device has a metal case. Any charge on the case must be able to move to earth.
(i) Draw one ring around a material that is suitable for the connection to earth.
| copper | glass | plastic | rubber |
|---|
(1 mark)
(ii) Explain your answer to (b)(i).
(1 mark)
A student rubs a polythene rod with a dry cloth. The polythene rod becomes negatively charged.
Describe and explain how the rod becomes negatively charged.
Extract:
A student rubs a polythene rod with a dry cloth. The polythene rod becomes negatively charged.
The negatively charged polythene rod hangs from a nylon thread so that it is free to turn.
The student charges a second polythene rod and brings it close to the first rod, as shown in Fig.11.1.
Describe and explain what happens when the negatively charged rods are close to each other.
A student experiments with electric charge.
The student uses a dry cloth to rub a plastic rod. The rod becomes positively charged.
Explain how the friction between the rod and the cloth causes the rod to become positively charged.
Use your ideas about the movement of charge.
Extract:
A student experiments with electric charge.
The student uses a dry cloth to rub a plastic rod. The rod becomes positively charged.
The student suspends a balloon from an insulating thread, as shown in Fig. 9.1.
The balloon has an electric charge.
Explain how the student can use a positively charged rod to determine the charge on the balloon.
The lamp of a car headlight is rated at 12 V, 50.0 W.
Calculate the current in the lamp when operating normally.
current = .........................................................
Extended tier only
A car is driven at night.
In a journey, the total charge that passes through the 12 V battery is 270 kC.
(i) Calculate the electrical energy transferred.
energy = ......................................................... [3]
(ii) The fuel used by the car provides 3.6 × 104 J / cm3.
Calculate the volume of fuel used to provide the energy calculated in (b)(i).
volume = ......................................................... [2]
Fig. 9.1 shows the symbol for a 12V battery.
Two lamps are connected in parallel with the battery.
On Fig. 9.1, using the correct symbols, complete the circuit diagram.
Extract:
Fig. 9.1 shows the symbol for a 12V battery.
Two lamps are connected in parallel with the battery.
One of these lamps has a resistance of 6.0 Ω.
One of these lamps has a resistance of 6.0 Ω.
Calculate, for this lamp:
(i) the current
current = ...........................................................[1]
(ii) the power.
power = ...........................................................[2]
Extract:
Fig. 9.1 shows the symbol for a 12V battery.
Two lamps are connected in parallel with the battery.
The power of the other lamp is 36 W.
Calculate the total energy delivered to this lamp in 20 hours.
energy = ...........................................................
Extended tier only
Fig. 9.1 shows current-potential difference graphs for a resistor and for a lamp.
(i) The potential difference (p.d.) applied to the resistor is increased. Tick the box that indicates the effect on the resistance of the resistor.
square resistance increases
square resistance is constant
square resistance decreases
(1 mark)
(ii) The potential difference (p.d.) applied to the lamp is increased. Tick the box that indicates the effect on the resistance of the lamp.
square resistance increases
square resistance is constant
square resistance decreases
(1 mark)
Extract:
Fig. 9.1 shows current-potential difference graphs for a resistor and for a lamp.
The p.d. across the lamp is 6.0V. Use the graph to obtain the current of the lamp when the potential difference is 6.0 V: The current is 4.4 A.
The p.d. across the lamp is 6.0V. Calculate the resistance of the lamp.
resistance = .........................................................
Extract:
The lamp and the resistor are connected in parallel to a 6.0 V supply. Current in the lamp = 4.4 A (at 6.0 V) Current in the resistor = 4.0 A (at 6.0 V) Total current in a parallel circuit = sum of the currents along each path.
The lamp and the resistor are connected in parallel to a 6.0 V supply.
Calculate the current from the supply.
current = .........................................................
Extract:
Use the graph to obtain the p.d. across the lamp when the current is 4.0 A:
Recall from part (c) the p.d. across the resistor when the current is 4.0 A:
Extended tier only
The lamp and the resistor are connected in series to another power supply. The current in the circuit is 4.0 A.
Calculate the total p.d. across the lamp and the resistor.
p.d. = .........................................................
Fig. 10.1 shows a circuit used by a student to test a metal wire made of nichrome.
State the name of component Z.
Extract:
Fig. 10.1 shows a circuit used by a student to test a metal wire made of nichrome.
The current reading on ammeter X is 0.8 A. State the reading on ammeter Y.
Extract:
Fig. 10.1 shows a circuit used by a student to test a metal wire made of nichrome.
The current in the nichrome wire is 0.8 A. The potential difference (p.d.) across the nichrome wire is 4.5 V.
Calculate the resistance of the nichrome wire.
resistance = ..................................................... Ω
Extract:
The current in the nichrome wire is 0.8 A. The potential difference (p.d.) across the nichrome wire is 4.5 V. Calculate the resistance of the nichrome wire. resistance = ..................................................... Ω
The student tests a different nichrome wire, which is thicker than the wire in (c), but of the same length. When testing this wire, the current in the wire is different from the value given in (c).
State and explain the difference in current.
Fig. 10.1 shows an electrical circuit.
(i) State the name for the component labelled X and state its function in this circuit.
(2 marks)
(ii) Describe how the circuit shown in Fig. 10.1 could be used to find the resistance of the fixed resistor R.
(3 marks)
An electrical heater has a resistance of 21.8 Ω when connected to a 240 V mains supply.
(i) Calculate the current in the heater.
current = ....................................................... A [3]
(ii) Suggest a rating for the fuse to be fitted to the mains plug for the heater.
fuse rating = ....................................................... A [1]
An uncharged conducting metal plate rests on insulating supports. Fig. 10.1 shows the plate and a positively charged insulating plastic sheet placed on top of the metal plate.
(i) Describe any flow of charge that takes place when the plastic sheet is placed onto the metal plate.
(1 mark)
(ii) On Fig. 10.1, draw how charges are now arranged within the metal plate.
(1 mark)
(iii) State and explain if this arrangement of charge helps to keep the plastic sheet in place.
(2 marks)
Fig. 10.2 shows two uncharged conducting spheres suspended on insulating threads.
The spheres are now both given positive charges. On Fig. 10.2, draw a possible position of each sphere and thread.
Explain the positions you have drawn.
Fig. 9.1 shows an electric circuit which includes uninsulated resistance wire XY. A teacher shows some students how to complete the circuit by placing the contact C at various positions on the wire XY.
The students place contact C at Y. They measure the current on the ammeter. Then they move the contact C along the wire from Y to X.
State and explain the effect on the ammeter reading when they move the contact C from Y to X.
Extract:
Voltage, V = 6.0 V Resistance, R = 8.0 Ω
Calculate the reading on the ammeter when contact C is at X.
ammeter reading = ...................................................... A
Extract:
The resistance of the wire between X and P is 20Ω. The fixed resistor is 8.0Ω.
The students move contact C to point P. The resistance of the wire between X and P is 20Ω.
Calculate the total resistance of the resistance wire between X and P and the fixed resistor.
total resistance = ..................................................... Ω
Fig. 7.1 shows a circuit containing a battery of e.m.f. 12 V and three resistors.
Fig. 7.1
The voltmeter measures the potential difference (p.d.) across the parallel combination of resistors.
Define potential difference (p.d.).
Extract:
Fig. 7.1 shows a circuit containing a battery of e.m.f. 12 V and three resistors.
A circuit diagram showing a 12-volt battery connected in series with resistor R1 and a parallel combination of resistors R2 and R3. A voltmeter is connected across the parallel combination. R1 has a resistance of 8 ohms, R2 has a resistance of 20 ohms, and R3 has a resistance of 30 ohms.
Show that the combined resistance of R2 and R3 is .
Extract:
Fig. 7.1 shows a circuit containing a battery of e.m.f. 12 V and three resistors.
The voltmeter measures the potential difference (p.d.) across the parallel combination of resistors.
R1 has a resistance of 8 ohms, R2 has a resistance of 20 ohms, and R3 has a resistance of 30 ohms.
Calculate the current in resistor R1.
Extract:
Fig. 7.1 shows a circuit containing a battery of e.m.f. 12 V and three resistors.
The voltmeter measures the potential difference (p.d.) across the parallel combination of resistors.
R1 has a resistance of 8 ohms, R2 has a resistance of 20 ohms, and R3 has a resistance of 30 ohms.
Explain how the reading on the voltmeter can be used to determine the p.d. across resistor R1.
State, in terms of their structure, why metals are good conductors of electricity.
Extended tier only
A cylindrical metal wire W1, of length and cross-sectional area A, has a resistance of 16 Ω.
A second cylindrical wire W2, of length and cross-sectional area 2A, is made from the same metal.
Determine
(i) the resistance of W2,
resistance of W2 = ...........................................................[2]
(ii) the effective resistance of W1 and W2 when connected in parallel
resistance of parallel pair = ...........................................................[2]
Extract:
A cylindrical metal wire W1, of length L and cross-sectional area A, has a resistance of 16 Ω. A second cylindrical wire W2, of length L/2 and cross-sectional area 2A, is made from the same metal.
(i) the resistance of W2: R_2 = 4 Ω
(ii) the effective resistance of W1 and W2 when connected in parallel: resistance of parallel pair = 3.2 Ω
Recall the equation for resistors in parallel: 1/R = 1/R_1 + 1/R_2
W1 and W2 are connected in parallel.
Extended tier only
The parallel pair of resistors in (b)(ii) is connected to a battery that is made from three cells in series, each of electromotive force (e.m.f.) E. There is a current in each resistor.
(i) State the e.m.f. of the battery.
(1 mark)
(ii) The current in the battery is IB, the current in W1 is I1 and the current in W2 is I2.
Place a tick in one box to indicate how these three currents are related.
square I1 > I2 > IB
square I1 > IB > I2
square I2 > I1 > IB
square I2 > IB > I1
square IB > I1 > I2
square IB > I2 > I1
square I1 = I2 = IB
(1 mark)
(i) Fig. 8.1 shows a positively charged cube of insulating material. The cube is fixed to a piece of wood that is floating on water. A negatively charged rod is held above the piece of wood and brought close to the cube, as shown.
State and explain any movement of the piece of wood.
(2 marks)
(ii) Fig. 8.2 shows two cubes of insulating material. One is positively charged and the other is negatively charged. The cubes are fixed to a piece of wood that is floating on water. Charged rods are held above the piece of wood and brought close to the cubes, as shown.
State and explain any movement of the piece of wood.
(2 marks)
In terms of a simple electron model, describe the differences between conductors and insulators.
Extended tier only
On Fig. 8.3, draw the electric field pattern around a single-point positive charge.
Extended tier only
(i) Describe what is meant by an electric field.
(1 mark)
(ii) State what is meant by the direction of an electric field.
(1 mark)
Fig. 8.1 shows a polystyrene ball covered with aluminium paint. The polystyrene ball is suspended between two charged metal plates by an insulated thread.
The ball oscillates between the two charged plates.
Explain why the ball oscillates.
Extended tier only
There is a current of 0.29 A in an electrical circuit.
Calculate the time taken for a charge of 15 C to flow through the electrical circuit.
time = .........................................................
Extended tier only
A light-emitting diode (LED) is a diode that emits light when there is a current in it.
Draw a circuit diagram showing an LED, connected so that it is lit, in series with a battery and a fixed resistor. Use standard electrical symbols.
Extract:
A light-emitting diode (LED) is a diode that emits light when there is a current in it.
The p.d. across the LED when lit is 3.1 V and the current in the LED is 0.030 A.
Calculate the value of the resistance of the LED when lit.
resistance = .........................................................
Fig. 8.1 shows a power supply of e.m.f. 10.5 V connected in series with a lamp and a heater.
The p.d. across the lamp is 2.1 V and the current in the lamp is 1.5 A.
Calculate:
(i) the resistance of the heater
resistance = ......................................................... [2]
(ii) the power of the heater.
power = ......................................................... [2]
Extended tier only
A light polystyrene ball is coated in conducting paint and suspended from a thread as shown in Fig. 1
The ball is given a positive charge
Fig. 1
Draw the electric field lines around the positively charged ball.
Extract:
A light polystyrene ball is coated in conducting paint and suspended from a thread as shown in Fig. 1
The ball is given a positive charge
A second, identical ball is suspended close to the first one. The second ball is also given a positive charge.
A student predicts that both balls will hang straight downward, due to the effect of gravity.
State whether the student is correct, and explain your answer.
Extract:
A light polystyrene ball is coated in conducting paint and suspended from a thread as shown in Fig. 1. The ball is given a positive charge. Draw the electric field lines around the positively charged ball.
A second, identical ball is suspended close to the first one. The second ball is also given a positive charge.
The student's prediction is: Both balls will hang straight downward, due to the effect of gravity. This prediction is: Wrong / incorrect; This is because: Both balls are positively charged; Like charges repel; Therefore the balls will be pushed apart.
(Sketch) Balls are hanging so that the threads point away from each other; Both balls have a radial field with arrows pointing away from their centre; Field lines extend into the area between the two balls; Field lines do not meet / there is an empty space.
Extended tier only
Sketch the arrangement of the two balls hanging next to each other.
Add field lines to your diagram, in support of your answer to part (b).
Fig. 9.1 shows a conducting ball that oscillates between two charged plates.
As the ball oscillates, it touches each plate in turn.
Referring to the charge on the ball, explain why the ball moves to the positive plate after touching the negative plate.
State which particles move when there is a current and state the direction in which they move through the sensitive ammeter.
Extended Tier Only
For each complete oscillation of the ball moving between the plates, a charge of 8.5 × 10–10 C is transferred from one plate to the other. The frequency of oscillation is 4.0 Hz.
Calculate the current shown on the sensitive ammeter.
current = ..........................................................