AQA GCSE Synergy Paper 4: Physical sciences Higher June 2024 question paper 8465/4H

A student investigated the magnetic effect of an electric current.

The student placed two iron rods inside a rectangular coil.

Figure 1 shows the equipment.

When the power supply is switched on there is a current in the rectangular coil.

Complete the sentence.

When there is a current in the rectangular coil, there is a magnetic field around the coil.

The magnetic field has a similar shape to the magnetic field around

The two iron rods repel each other when there is a magnetic field around the coil.

Explain why.

The two iron rods are replaced with copper rods.

The two copper rods remain stationary when there is a magnetic field around the coil.

Give one reason why.

The student made an electromagnet by: wrapping a coil of wire around an iron bar connecting the coil of wire to a power supply.

The student investigated how the current in the electromagnet affected the strength of the electromagnet.

Figure 2 shows the electromagnet.

Enlarge

The student arranged a newtonmeter and an iron disc above the electromagnet.

Figure 3 shows the equipment.

The power supply is switched off.

Why is the newtonmeter reading 2.0 N?

Tick (✓) one box.

The weight of the electromagnet is 2.0 N.

The weight of the iron disc is 2.0 N.

The weight of the newtonmeter is 2.0 N.

The student switched the power supply on and then increased the current in the electromagnet.

The iron disc was not touching the electromagnet, but the reading on the newtonmeter changed.

Explain why.

The student recorded the readings on the newtonmeter as the current increased.

Figure 4 shows the results.

The student wrapped twice as many turns of wire around the iron bar and repeated the investigation.

Draw a line on Figure 4 to show the expected results.

A student investigated the reactivity of four metals with sulfuric acid.

Figure 5 shows the apparatus.

Give two variables the student should control.

Write the order of reactivity from least reactive to most reactive for the four metals.

Use Figure 5.

The gas produced in Figure 5 is hydrogen.

Describe the test for hydrogen gas.

Give the result if hydrogen is present.

The student repeated the investigation using different apparatus to determine the rate of reaction.

Figure 6 shows part of the apparatus.

Complete Figure 6 so that the apparatus can be used to determine the rate of reaction.

Give two measurements the student should make to determine the rate of reaction.

What is the unit for the rate of reaction determined using the apparatus in Figure 6?

A thermistor is an electrical component.

What is the circuit symbol for a thermistor?

Tick (✓) one box.

A student investigated how the resistance of a thermistor varies with temperature.

Figure 7 shows the results.

Suggest why the student was not able to take measurements at temperatures below 20 °C.

The student used an ammeter and a voltmeter to take measurements to determine the resistance of the thermistor.

Describe a method the student could have used to obtain the results shown in Figure 7.

Figure 7 is repeated below.

Use the Physics Equations Sheet to answer Questions 03.4 and 03.5.

Write down the equation which links current (I), potential difference (V) and resistance (R).

The potential difference across the thermistor was 6.0 V.

Determine the current in the thermistor when the temperature of the thermistor was 40 °C.

Use Figure 7.

A skydiver jumped out of a helicopter.

Figure 8 shows a distance-time graph for the first 12 seconds after the skydiver jumped out of the helicopter.

Determine the speed of the skydiver between 8 and 12 seconds.

Use the Physics Equations Sheet.

Describe how the motion of the skydiver changed between 0 and 12 seconds.

Explain why the resultant force on the skydiver changed as the skydiver fell.

Which of the velocity–time graphs shows how the velocity of the skydiver changed after the parachute was opened?

Tick (✓) one box.

This question is about electrolysis.

Figure 9 shows the electrolysis of molten potassium chloride using inert electrodes.

Why must potassium chloride be molten during the electrolysis?

Why are inert electrodes used in electrolysis?

A gas is released during the electrolysis of molten potassium chloride.

Describe the test to identify the gas released.

Give the result if the gas is present.

Potassium is produced at the negative electrode.

Write the half equation for the reaction at the negative electrode during the electrolysis of molten potassium chloride.

What type of reaction occurs at the negative electrode?

An aqueous solution of potassium chloride was electrolysed.

Hydrogen gas was produced at the negative electrode.

Explain why hydrogen gas is produced during the electrolysis of an aqueous solution of potassium chloride.

50 cm³ of potassium chloride solution contains 0.030 moles of potassium chloride.

Calculate the concentration of the potassium chloride solution in g/dm³.

Relative formula mass (M_r) of potassium chloride = 74.5

Concentration = g/dm³ _________________

A cordless hairdryer contains a heating element and a fan.

The hairdryer is powered by a rechargeable battery.

Figure 10 shows the cordless hairdryer.

The power output of the heating element is 0.24 kW when the potential difference across the heating element is 16 V.

Calculate the current in the heating element.

Use the Physics Equations Sheet.

The battery of the hairdryer can be recharged from 0 to 100% in 6.0 hours.

The power input to the battery is 18 W.

The potential difference across the battery is 24 V.

Calculate the charge flow through the battery in 6.0 hours.

Use the Physics Equations Sheet.

Figure 11 shows a floating hot air balloon attached to the ground by a rope.

The hot air balloon is stationary.

The wind is exerting a force on the hot air balloon in Figure 11.

Which direction is the force of the wind acting?

What is the name of the upwards force on the hot air balloon?

The weight of the hot air balloon is 3.43 kN.

gravitational field strength = 9.8 N/kg

Calculate the mass of the hot air balloon.

Use the Physics Equations Sheet.

The resultant force on the balloon is zero.

What is meant by ‘resultant force’?

Figure 12 shows a vector diagram of the force of the rope on the hot air balloon.

Scale 1 cm = 50 N

Complete the vector diagram to determine the magnitude of the horizontal and vertical components of the force.

This question is about acids and salts.

Nitric acid is a strong acid.

A solution of nitric acid can be dilute.

Explain how nitric acid can be both strong and dilute.

The pH value of a solution of nitric acid increases by 1.

How does the hydrogen ion concentration of the solution change?

Tick (✓) one box.

Decreases by a factor of 10

Decreases by a factor of 100

Increases by a factor of 10

Increases by a factor of 100

Question 8 continues in the next page

A student reacted nitric acid with excess calcium carbonate.

The word equation for the reaction is:

calcium carbonate + nitric acid calcium nitrate + water + carbon dioxide

This is the method used.

1. Measure 100 cm³ of nitric acid into a beaker.

2. Add calcium carbonate powder to the nitric acid.

3. Stir the mixture.

4. Repeat steps 2 and 3 until the calcium carbonate is in excess.

5. Filter the mixture.

Describe the additional steps that should be included in the method to determine the mass of calcium carbonate that reacted.

The formula of nitric acid is HNO₃

Which expression gives the percentage (%) by mass of oxygen in HNO₃?

Relative atomic mass (A_r): O = 16

Relative formula mass (M_r): HNO₃ = 63

Tick (✓) one box.

What is the formula of calcium nitrate?

Use the periodic table.

Tick (✓) one box.

CaNO₃

Ca(NO₃)₂

Ca₂NO₃

Ca₂(NO₃)₃

Question 8 continues in the next page

Magnesium chloride is a salt.

Calculate the number of magnesium ions in 47.5 g of magnesium chloride (MgCl₂).

Relative atomic masses (A_r): Mg = 24 Cl = 35.5

Avogadro constant = 6.02 × 10²³ per mole

A student investigated electrical circuits.

The student changed the position of the voltmeter.

Figure 14 shows the new circuit.

The student connected the voltmeter across the 15 Ω fixed resistor.

The student used the variable resistor to vary the potential difference across the fixed resistor.

The potential difference across the fixed resistor can only be varied between 6 V and 12 V using the circuit in Figure 14.

Explain why.

Give one way the student could vary the potential difference across the fixed resistor below 6 V.