IGCSE_Edexcel_Past_Papers_4ph1-1p-que-20230526

Questions 1

(a) Topic – 8.a

(b) Topic-8.b

This is a question about radioactivity.
(a) Which of these is the unit of activity?
A becquerel
B kilogram
C newton
D pascal
(b) Which of these is the correct description of the term half-life?
A time taken for the activity of a substance to halve
B half of the time taken for the mass of a substance to decay
C time taken for the activity to decay completely
D time taken for the mass of a substance to decay twice

(c) A teacher demonstrates how the activity of a radioactive sample changes with time.
(i) The box gives the names of different pieces of equipment.

Complete the sentences using words from the box.
The teacher measures time with a …………………………………………………….. . The teacher measures the count rate with a …………………………………………………….. and a counter.

(ii) The graph shows the teacher’s results.

Draw a circle around the anomalous result.
(iii) Use the graph to determine the half-life of the radioactive sample.

(iv) Give a reason why the teacher should not expect the data points to lie exactly on the curve of best fit.

▶️Answer/Explanation

Ans

(a) A (becquerel);
B is incorrect because it is the unit of mass
C is incorrect because it is the unit of force
D is incorrect because it is the unit of pressure

(b) A (time taken for the activity of a substance to halve);
B is incorrect because the substance will not completely decay
C is incorrect because the substance will not completely decay
D is incorrect because the substance cannot decay twice

(iii) any indication of a halving in activity;

half-life = 15 (s);

(iv) any indication that decay is random;

Questions 2

(a) Topic – Appendix 7: Electrical circuit symbols

(b) Topic- 2.c

A student investigates how the current in a filament lamp changes when the voltage across the lamp is varied.
(a) Draw a circuit diagram the student could use in their investigation.

(b) The graph shows the student’s results.

(i) Describe the relationship between current and voltage shown on the graph.

(ii) State the formula linking resistance, voltage and current.

(iii) Use the graph to determine the resistance of the filament lamp when the voltage across the lamp is 7.2V.

▶️Answer/Explanation

Ans

(a) correct circuit symbols for all of;
• suitable power source
• ammeter
• voltmeter
• filament lamp

ammeter drawn in series with lamp;
voltmeter drawn in parallel with lamp;

means of varying current or voltage i.e. variable resistor/variable power supply;

(b) (i) current increases as voltage increases;

idea of non-linear relationship;

(ii) voltage = current × resistance;

(iii) substitution;

rearrangement;

evaluation;

e.g.
7.2 = 2.40 × R
R = 7.2/2.40
R = 3.0 (Ω)

Questions 3

(a) Topic – 2.b

(b) Topic-2.b

A family has a television set.
(a) The television set has a low power mode called standby. When on standby, the power rating of the television set is 0.27W. Calculate the energy transferred to the television set on standby in 12 hours.

(b) In normal use, the current in the television set is 0.31A.
(i) Explain how a fuse works to protect the television set if there is a fault.

(ii) Explain why a 13A fuse is not an appropriate choice of fuse to use in the plug of this television set.

▶️Answer/Explanation

Ans

(a) substitution into given formula;

rearrangement;
correct evaluation;

e.g.
0.27 = energy / 43 200
energy = 0.27 × 43 200
(energy =) 12 000 (J)

(b) (i) idea that current exceeds the fuse rating;

fuse (wire) melts;

idea that device is isolated;

(ii) any two from:
MP1. idea that fuse rating is much higher than normal current;
MP2. idea that there is still current (even if there is a fault);
MP3. idea that (connecting lead/TV) will overheat/cause a fire;

Questions 4

(a) Topic – 5.b

(b) Topic-5.b

Ground-penetrating radar (GPR) uses radio waves to detect changes in material underground.
(a) (i) State the formula linking the speed, frequency and wavelength of a wave.
(ii) GPR radio waves have a frequency of 170MHz. The speed of radio waves is \(3.0 × 10^8 m/s\). Calculate the wavelength of the waves.

(b) (i) A radio wave passes through the ground and refracts at the boundary between soil and rock. The diagram shows three wavefronts of the wave before and after refraction. The wave is also reflected at the boundary between the soil and the rock. Complete the diagram to show three wavefronts after the wave has been reflected at the boundary.

(ii) Explain why the radio waves passing through the rock have a smaller wavelength than the radio waves passing through the soil.

▶️Answer/Explanation

Ans

(a) (i) speed = frequency × wavelength;

(ii) substitution;
rearrangement;
evaluation;

e.g.
\(3.0 × 10^8 = 170 (× 10^6) × λ\)
λ = v/f OR \(λ = 3.0 × 10^8/170 (× 10^6)\)
(wavelength =) 1.8 (m)

(b) (i) reflected ray/wavefronts drawn to right of ‘normal’ and above rock;

wavefronts perpendicular to reflected ray;

wavefronts parallel to each other and spacing consistent with incident wavefronts;

(ii) any three from:

MP1. wavefronts closer together;

MP2. idea that rock is (optically) denser than soil;

MP3. idea of reduction in speed;
MP4. idea of constant frequency;
MP5. correct reference to wave speed equation / speed = frequency × wavelength;

Questions 5

(a) Topic – 4.b

(b) Topic- 4.b

The drawing shows a camel and a person in a desert.

(a) Describe a method you could use to find the pressure a person exerts on the ground when standing on two feet.

(b) The total area of contact of the camel’s feet with the ground is 1300 cm². The mass of the camel is 660kg. Calculate the pressure this camel exerts on the ground.

▶️Answer/Explanation

Ans

(a) any four from:
MP1. measurement of area of foot/feet;
MP2. idea of drawing round foot/feet on squared/grid/graph paper (to measure area);
MP3. measurement of weight / use of W = mg;
MP4. use of a balance / scale(s) (to measure weight/mass);
MP5. use of p = F ÷ A;

(b) weight = 6600 (N);

substitution into p = F / A;
correct evaluation;

e.g.
weight = 660 × 10 = 6600 (N)
pressure = 6600 / 1300
(pressure =) 5.1 N/cm²)

Questions 6

(a) Topic – 5.c

(b) Topic- 4.b

The photograph shows an x-ray image of a person’s knee. The person has had part of their knee replaced.

(a) X-rays are part of the electromagnetic spectrum. All electromagnetic waves are transverse waves and transfer energy.
(i) State another property that all electromagnetic waves have in common.
(ii) State a harmful effect of excessive exposure to x-rays.

(iii) Describe the difference between transverse waves and longitudinal waves. You may draw a diagram to help your answer.

(b) The diagram shows a part of the knee called the patella. The patella has been removed from a person’s knee.

The patella is a small, irregularly shaped bone that is denser than water. Describe how to find the mass and the volume of the patella bone.

(c) A scientist finds the volume and mass of a patella. The mass of the patella is 17g. The volume of the patella is \(13cm^3\). Calculate the density of the patella. Give your answer to 2 significant figures.

▶️Answer/Explanation

Ans

(a) (i) (travel at) {same speed/speed of light/in vacuum};
OR
idea that waves can travel through space / a vacuum;

(ii) (excessive exposure may cause) cancer;

(iii) mention of oscillations/vibrations;
{oscillation/vibrations/particle movement} are parallel to {direction of wave (travel) / direction of energy transfer} of wave for longitudinal;
{oscillation/vibrations/particle movement} are perpendicular to {direction of wave (travel) / direction of energy transfer} of wave for transverse;

(b) use of relevant pieces of measuring apparatus for mass AND volume;

idea of use of displacement method for volume;

further correct detail of displacement method;

further experimental accuracy detail;

(c) correct formula selected;
substitution;
evaluation;
answer given to 2 sf;
e.g.
density = mass / volume
density = 17 / 13
density = 1.3… (g/cm³)
density = 1.3 (g/cm³)

Questions 7

(a) Topic – 3.c

(b) Topic- 3.c

(d) Topic- 3.b

The circuit diagram shows a motor, power supply, switch and variable resistor connected in series.

(a) The switch is open and the motor is not moving. State how much energy is in the kinetic energy store of the motor.
(b) The switch is closed. The motor takes 0.42 seconds to reach its maximum speed of rotation. The mean current in the motor is 3.9A. The voltage across the motor is 7.1V. Show that the work done on the motor during the 0.42 seconds is about 12J.

(d) Use the Sankey diagram to calculate the efficiency of the process of bringing the motor to its maximum speed of rotation.

▶️Answer/Explanation

Ans

(a) 0 / none / zero (J);

(b) substitution into given formula E = V × I × t;

correct evaluation to at least 3 s.f.;
e.g.
energy = 7.1 × 3.9 × 0.42
energy = 11.6… (J)

kinetic energy store of motor 10 J;
thermal store of the surroundings 2 J;

(d) useful and total energies correctly selected;
substitution into efficiency formula;
evaluation;

e.g.
10 (J) and 12 (J) seen in working
efficiency = 10/12 (×100%)
efficiency = 83 (%)

Questions 8

(a) Topic – 5.d

(b) Topic-2.d

In some countries, snow can fall and collect on the ground. Diagram 1 shows that after the snow has fallen, the sky can be clear, leaving the snow directly exposed to the Sun.

(a) Explain why the white snow will take a long time to melt, even though directly exposed to the Sun.

(b) Diagram 2 shows a different piece of ground that has a metal drain cover. If the snow lands on metal, the snow takes a shorter time to melt.

Explain why the snow melts in a shorter time on the metal drain cover.

▶️Answer/Explanation

Ans

(a) any reference to absorption or reflection (of infrared/heat);
idea that snow/white objects are poor
absorbers/good reflectors (of infra-red/heat);

(b) any two from:
MP1. idea that ground / drain cover is warmer than snow;
MP2. idea that drain cover / metal is a good conductor;
MP3. energy transfers from drain cover to snow;

(c) any two from:
MP1. idea that warmer air rises;
MP2. idea that colder air is nearest the snow; ignore nearest the ground
MP3. (rate of) energy/heat transfer (from air) to snow decreases;

Questions 9

(a) Topic – 4.b

(b) Topic- 1.c

A manometer is a device that can be used to measure the pressure difference between gas from a gas tap and the atmosphere. When a gas tap is connected to the manometer, the liquid in the manometer moves due to the additional pressure of the gas.

(a) The pressure difference is linked to the difference in height of the two surfaces of the liquid by the formula
pressure difference = density × g × height difference
The height difference between the two surfaces is 0.094m. Calculate the pressure difference between the gas from the gas tap and the atmosphere. [for liquid, density = 14000kg/m3 ]

(b) The graph shows how the velocity of the surface of the liquid changes with time from when the gas tap is opened to when the water level stops moving.

(i) Use the graph to show that the distance travelled by the surface of the liquid is 4.7cm.
(ii) Calculate the acceleration of the surface of the liquid.

(c) Explain how the gas pressure changes if the temperature of the gas increases. You should use ideas about particles in your answer.

▶️Answer/Explanation

Ans

(a) substitution into given formula;

evaluation;

e.g.
pressure difference = 14 000 × 10 × 0.094
pressure difference = 13 000 (Pa)

(b) (i) idea that distance is area under graph;

correct values read from graph;

working arriving at 4.7 (cm);

(ii) any viable attempt at a gradient; allow use of \(v^2=u^2 + 2as\)
correct use of 47 and 0.20 in gradient calculation;

acceleration in range (−)230 to (−)240 (cm/s²);

(c) idea of (gas) particles speeding up;
idea of more frequent collisions between particles
and liquid/walls/container;
idea of harder collisions between particles and
liquid/walls/container;

Questions 10

(a) Topic – Experimental skills

(b) Topic-1.b

A student investigates how the time taken for a ball to roll down a slope changes with the distance from the bottom of the slope. This is the student’s method.
• place a ball on the slope 10cm from the bottom of the slope
• release the ball and start a stopwatch
• stop the stopwatch when the ball arrives at the bottom of the slope
• record the time taken for the ball to roll down the slope
• repeat for different distances from the bottom of the slope
(a) Complete the table by placing a tick (ü) to show which variables are the independent, dependent and control variables in this investigation.

(b) The table shows the student’s results.

(i) Plot the student’s data on the grid.
(ii) Draw a best fit curve.

(iii) The student concludes that the results obey this relationship
distance ÷ (time²) = constant
Use the student’s data to deduce whether the student’s results support this conclusion.

▶️Answer/Explanation

Ans

(a) one mark for each correct row;;;;

(b) (i) all points correct;

(ii) curve goes through all points;

(iii) constant correctly calculated for one row of table;
constant correctly calculated for another row of table;
statement/expression comparing constants;
consistent conclusion about relationship based on comparison of constants;

Questions 11

(a) Topic – 2.c

(b) Topic- 2.c

Diagram 1 shows a light-emitting diode (LED) and a resistor in series with a cell and an ammeter.

(a) The voltage across the LED is 0.63V. Calculate the current in the circuit. Give your answer in milliamps.

(b) Diagram 2 shows a second LED and an extra resistor connected in parallel with the cell.

The resistor and the LED are the same as the components used in diagram 1. The two resistors are identical and the two LEDs are identical. Explain how the ammeter reading will change

▶️Answer/Explanation

Ans

(a) idea that voltage across resistor is difference between cell and diode voltage;
rearrangement of V = IR;
evaluation in A;
conversion to mA;

e.g.
voltage across resistor = 1.5 − 0.63 = 0.87 (V)
I = V/R = 0.87/95
current = 0.00915… (A)
current = 9.2 (mA)

(b) any four from:
MP1. resistance (of circuit) decreased;
MP2. (because) extra path in circuit;
MP3. resistance (of circuit) halved;

MP4. idea that voltage across parallel branches is the same (as previous voltage);
MP5. current (in ammeter) increased;
MP6. current (in ammeter) doubled;

Questions 12

(a) Topic – 2.b

(b) Topic- 2.b

A device called a metal detector can be used to find metal buried underground.

The metal detector has two circuits, each containing a coil of copper wire. Diagram 1 shows the circuit for the transmitter coil.

(a) Suggest why there is a magnetic field around the transmitter coil.
(b) The cell supplies direct current (d.c.). The electronics in diagram 1 change the direct current into alternating current (a.c.) in the coil.
(i) Describe the difference between direct current (d.c.) and alternating current (a.c.).

(ii) Alternating current is supplied to the transmitter coil. Diagram 2 shows a gold ring in the soil below the metal detector.

Explain why there is an alternating current in the gold ring.

As a result of the alternating current in the gold ring, there is an alternating current in the receiving coil. Explain how an alternating current in the receiving coil causes a sound to be emitted from the loudspeaker.

▶️Answer/Explanation

Ans

(a) idea of a current (in the coil);

(b) (i) d.c. travels in one direction only;
idea of a.c. continuously changing direction;

(ii) idea of changing magnetic field (from transmitter coil);
idea of gold ring cutting field lines;

idea of induced voltage for gold ring;

(c) any four from:
MP1. alternating current in loudspeaker;
MP2. magnetic fields interact (in loudspeaker);
MP3. causing a force (on loudspeaker cone);
MP4. a.c. causes changing force direction;
MP5. loudspeaker (cone) vibrates;

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