AQA GCE AS Level Physics AS Paper 2 June 2023 question paper 7407/2

Figure 1 shows a micrometer screw gauge.

What is the reading on the micrometer?

Tick (✓) one box.

A metal wire of diameter d is held in the gap between the anvil and the spindle. Just before the reading of d is taken, the gap is closed using the ratchet and not the thimble.

Explain why the gap is closed in this way.

The mass per unit length μ of the metal wire is given by

where ρ is the density of the metal.

Values of d and μ are used to calculate ρ.

The percentage uncertainty in d is 1.2%. The percentage uncertainty in μ is 2.0%.

Calculate the percentage uncertainty in the result for ρ.

Figure 2 shows apparatus used to investigate how the frequency of stationary waves on a wire depends on its diameter d.

When the signal generator is switched on, the horizontal part of the wire oscillates.

A student changes the frequency until the first-harmonic stationary wave is produced. The student records the frequency f of the first harmonic and then turns off the signal generator. She removes the wire and measures d using a micrometer.

She then repeats the experiment for wires of different diameter.

The wires used in the experiment are made of the same metal so that ρ is a control variable.

State two other control variables in the experiment.

Figure 3 is a plot of the experimental data.

The student suggests that f .

Deduce, using data points from Figure 3, whether this suggestion is correct.

Another student repeats the experiment with the mass of M doubled.

Explain how this student’s plotted data compare with Figure 3.

Figure 4 shows an arrangement used to investigate projectile motion of a ball.

The ball is placed on the track at the release point. The ball is released from rest from a vertical distance h above the table.

When the ball reaches the end of the track, it is a vertical distance H above the horizontal floor. The ball leaves the track horizontally and lands on the floor at a horizontal distance x from the end of the track.

To measure x a student must locate a point P on the floor vertically below the end of the track.

Describe a procedure to locate P. You may add detail to Figure 4 to illustrate your answer.

A ruler, graduated in mm, is used to determine x. The student places the ruler on the floor with the zero graduation aligned with P.

The student determines x when the ball is released six times at a particular value of h He makes marks on the floor where the ball lands.

Figure 5 shows circles that indicate these marks.

Determine x for this value of h.

The student obtains values of x corresponding to other values of h. Figure 6 shows his results.

Determine H.

In a different arrangement, the ball is released from rest and then continues to roll at a constant velocity across a horizontal table, as shown in Figure 7.

The bottom of the track is fixed to the table at point Q. The angle between the straight part of the track and the table is α. A marker is placed at R, a point midway between Q and the edge of the table.

The student uses a stopwatch to measure the time t for the ball to roll from Q to R.

Explain why increasing the distance QR will reduce the percentage uncertainty in t.

Figure 8 shows values of t for different values of α.

At a particular value of α the ball rolls from Q to R at its maximum velocity.

Explain how the student should use Figure 8 to determine this value of α. Go on to suggest what further readings should be taken to reduce the uncertainty in this value of α.

Figure 9 shows a spoon used to measure the mass of food.

The empty spoon balances when a pivot is placed under a point P halfway along the spoon.

The spoon tilts when food of mass M is placed in the bowl. The spoon is rebalanced by moving the pivot a distance x to the right of P. The new position of the pivot is under point Q in Figure 10.

The total length of the spoon is 32.0 cm. The weight of the food acts through a line at a distance of 4.0 cm from the right-hand edge of the spoon.

Explain why the spoon in Figure 10 is balanced when the pivot is at Q.

The empty spoon has mass m.

Show that, for the arrangement in Figure 10,

Figure 11 shows how x varies with M.

Determine, using Figure 11, the weight of the empty spoon.

A scale, in grams, is marked on the spoon between P and the bowl. Figure 11 is used to calibrate this scale in intervals of 25 g.

M can be measured by balancing the spoon. The value is read from the point of the scale directly above the pivot.

State and explain how the uncertainty in the value read from the scale changes as M increases.

Figure 12 shows a type of refractometer. A semi-circular glass block is arranged so that its semi-circular faces are vertical. A drop of liquid is placed at the centre of the flat horizontal surface of the block.

Light enters the block through the curved surface and is incident on the midpoint of the horizontal surface at angle of incidence θ. Light that reflects at the glass–liquid boundary is detected on a screen that lies parallel to the horizontal surface.

Explain why the light ray in Figure 12 does not change direction as it enters the block.

The refractometer is calibrated using a drop of liquid. When θ = 15°, light is partially refracted at the glass–liquid boundary.

Calculate the angle of refraction at this boundary.

refractive index of glass block = 1.84 refractive index of liquid = 1.33

The refractometer is used to determine the critical angle θ_c at the glass–liquid boundary.

Figure 13 shows dimensions of the arrangement.

The intensity of the light ray on the screen is observed as θ is increased from 15°. When θ = θ_c the intensity of the light ray is seen to increase sharply at a point T on the screen.

The distance between the left-hand edge of the screen and T is x.

Explain why the intensity of the light ray on the screen increases at T.

The liquid is replaced with a drop of sugar solution. The refractive index of the sugar solution is greater than 1.33

Deduce how this change affects the position at which the sharp increase in intensity is observed on the screen.

The refractometer in Figure 13 is used to determine the concentration of a sugar solution.

Figure 14 shows the variation of refractive index with concentration of sugar solution.

For a drop of a particular sugar solution, x = 69 mm.

Determine the percentage concentration of the sugar solution.

refractive index of glass block = 1.84

Each of Questions 05 to 34 is followed by four responses, A, B, C and D.

For each question select the best response.

Light of wavelength λ is incident normally on a diffraction grating. The separation between adjacent slits is equal to 5λ.

What is the smallest angle between the third-order maximum and fourth-order maximum diffracted beams?

S₁ and S₂ are coherent sources of microwaves that produce waves of the same amplitude. A microwave detector gives a zero reading when placed at a point that is the same

What is the phase difference between microwaves from S₁ and S₂ at the detector?

Powder is spread along the inside of an air-filled pipe that is closed at one end. A loudspeaker is placed at the other end. At certain sound frequencies a stationary wave is produced so that powder collects in evenly spaced piles. These piles correspond to positions of minimum amplitude.

The distance between pile A and pile B is 0.20 m.

What is the wavelength of the stationary sound wave?

An object of mass 0.20 kg moves with an initial velocity u. It collides with a stationary object of mass 0.30 kg.

The objects stick together when they collide. No external forces act on the objects.

What is the final velocity of the two objects after the collision?

P and Q represent displacements.

What is the resultant displacement when P and Q are added?

A girl kicks a football vertically upwards at time t = 0

Air resistance is negligible.

What is the variation of the vertical component of velocity v of the football with t until it

A cell with negligible internal resistance is connected to two resistors of resistance 4 R and R. The currents I₁, I₂ and I₃ in the circuit are shown.

Which equation is correct for this circuit?

The four lowest energy levels of an atom are shown.

A gas contains atoms in the n = 4 level. The atoms de-excite to the n = 1 level.

How many photon frequencies are observed?

Monochromatic light of frequency f is incident on a metal surface in a vacuum. Photoelectrons are emitted from the surface.

The photoelectric current I is measured.

The magnitude of the stopping potential V_s is then measured.

f is increased without changing the rate at which photons arrive at the metal surface.

What are the new measurements of the photoelectric current and the magnitude of the

An electron and a positron annihilate each other.

Which quantity is not conserved in the annihilation?

Which exchange particle transfers charge during electron capture?

A free neutron decays to produce a proton and

Two aerials A₁ and A₂ receive radio waves from the same distant transmitter T. The waves have a frequency of 88 MHz. The phase difference between the waves received by A₁ and A₂ is 6.6 rad.

A circuit contains a thermistor and a resistor in parallel. The internal resistance of the cell is negligible.

The temperature of the thermistor is increased. The temperature of the resistor is kept constant.

What is observed on the voltmeter and the ammeter?

The table shows the lengths and cross-sectional areas of two wires X and Y of the same

The resistance of X is 6.0 Ω. The temperature of Y is the same as the temperature of X.

What is the resistance of Y ?

A superconducting material has a critical temperature T_c.

Which graph shows the variation of resistivity ρ with temperature T ?

X, Y and Z are three networks of resistors.

Which gives the networks in order of largest total resistance to smallest total resistance?

subsequently decays in two stages to form a nucleus of nuclide X. One beta-minus particle and one alpha particle are emitted during these two decays.

What are the nucleon number and the proton number of X ?

The concept of exchange particles was introduced to explain forces between elementary particles.

This concept requires that exchange particles have

A stationary wave of wavelength λ is produced on a string.

What are the phase difference and the distance between adjacent antinodes?

A central diffraction maximum is observed when monochromatic light of wavelength λ passes through a single slit of width s.

Which combination of changes to λ and s will always produce a wider central diffraction

A ball is dropped from a height h. The ball hits the ground with a velocity v.

The ball is now dropped from a height of 2 h. Air resistance is negligible.

What is the velocity at which the ball hits the ground?

The graph shows the variation of stress with strain for a material.

What is the Young modulus of the material?

Which row shows the resistance of an ideal ammeter and of an ideal voltmeter?

The current in a resistor is 15 mA.

How many electrons pass through the resistor in 3 minutes?

Three resistors are connected in series with a 9.0 V battery of negligible internal resistance.

The resistance of the variable resistor is varied from 0 to 3.0 kΩ.

The range of potential difference observed on the voltmeter is

The current–voltage characteristic between 0 and 6.0 V is required for a filament lamp. The lamp is connected in a circuit with a battery of emf 6.0 V and negligible internal resistance.

Which circuit should be used?

The diagram shows a circuit containing three resistors X, Y and Z.

X and Y each have resistance R. Z has resistance 2 R.

A pellet of mass 25 g travelling horizontally at 40 m s⁻¹ enters a fixed wooden block. The pellet stops after travelling a horizontal distance of 2.5 cm in the block.

What is the average resistive force acting on the pellet?

The graph shows the variation of force with distance between a proton and a neutron.

The shaded area represents