OCR GCE AS Level Physics A AS Paper 1 November 2020 question paper H156/01

One of Kirchhoff’s laws is stated below.

The sum of the currents entering a point in a circuit is equal to the sum of the currents leaving the same point.

Which quantity is conserved according to this law?

A charge

B energy

C mass

D potential difference

An object is in equilibrium under the action of three coplanar forces F, R and W. The diagram below shows the forces F and W.

The angle between F and W is 90°.

Which row shows the correct magnitude of R and the approximate direction of R ?

A ball, made from scrunched-up paper, is dropped from rest at time t = 0. It reaches terminal velocity before it hits the ground.

Which acceleration a against time t graph is correct for the ball in flight?

The diagram below shows the oscilloscope trace for an electrical signal.

The frequency of the signal is 250 Hz.

What is the time-base setting of the oscilloscope?

A 1 ms cm⁻¹

B 2 ms cm⁻¹

C 4 ms cm⁻¹

D 8 ms cm⁻¹

This question is about progressive waves and stationary waves.

Which statement is not correct?

A A progressive wave transports energy through space.

B A stationary wave must have at least one node.

C For both waves, the amplitude of the oscillation is the same everywhere along the wave.

D In the stationary wave, the oscillations of the particles at two adjacent antinodes are out of phase by 180°.

A proton has kinetic energy 8.00 × 10⁻¹⁷ J.

Which is the correct expression for the de Broglie wavelength of the proton?

The diagram below shows an electrical circuit.

The resistance of each resistor is shown. All resistors are made from the same material and have the same diameter. The mean drift velocity of the charge carriers in the 100 resistor is v.

What is the mean drift velocity of the charge carriers in the 300 resistor?

A 0.40 v

B 0.50 v

C 0.60 v

D 1.00 v

A 0.30 kg mass is hung from a spring. The length of the spring is now 16.0 cm. The length of the spring becomes 17.5 cm when an additional 0.20 kg mass is hung from the spring. The spring obeys Hooke’s law.

What is the force constant of the spring?

A 11 N m⁻¹

B 12 N m⁻¹

C 130 N m⁻¹

D 330 N m⁻¹

A uniform beam is initially lying on horizontal ground, as shown below.

The end X of the beam is hinged. The beam is tilted from angle = 0 to = 90°. The moment of the weight of the beam about point X is M.

Which M against graph is correct?

A small block of wood is placed in deep water. The block is at rest with 80% of its volume under the surface of water. The weight of the block is 6.0 N.

What is the upthrust acting on the block?

A 0

B 1.2 N

C 4.8 N

D 6.0 N

The momentum of an object moving to the left is 28 kg m s⁻¹. A force of magnitude 3.5 N acts on the object to the right for a time of 2.0 s.

What is the change in the momentum of the object?

A 7.0 kg m s⁻¹

B 21 kg m s⁻¹

C 28 kg m s⁻¹

D 35 kg m s⁻¹

A driver sees an obstacle ahead in the road at time t = 0 and then applies the brakes. The velocity v against time t graph for the car is shown below.

A seabird dives vertically into water. The seabird is briefly stationary at its greatest depth. In water, the upthrust on this seabird is always greater than the weight of the seabird.

Which statement is correct at the instant of greatest depth?

A The seabird experiences greatest drag.

B The seabird has an upward acceleration.

C The upthrust on the seabird is equal to drag.

D The weight of the seabird is equal to drag.

A uniform beam has length 0.80 m and weight W. The beam is hinged at point H. A cable is attached to the beam at a distance x from H. The vertical upwards force in the cable is 0.75 W. The cable is not shown in the diagram. The beam is at rest in the horizontal position.

Which condition is correct?

A x < 0.40 m

B x = 0.40 m

C 0.40 m < x < 0.80 m

D x = 0.80 m

What is the S.I. unit for electrical charge?

A ampere

B coulomb

C ohm

D volt

Which pair of quantities have the same S.I. base units?

A force, energy

B moment, momentum

C power, work done

D work done, moment

A stationary sound wave, of fundamental mode of vibration, is formed in a tube closed at one end.

The length of the tube is 0.17 m. The speed of sound in air is 340 m s⁻¹.

What is the fundamental frequency of the stationary wave?

A 500 Hz

B 1000 Hz

C 2000 Hz

D 4000 Hz

Two objects collide. The collision is perfectly elastic.

State two quantities that are conserved in this type of collision.

The diagram below shows a person on a horizontal skateboard holding a heavy ball.

The person is initially stationary. The person throws the ball horizontally to the right.

Describe and explain the motion of the person on the skateboard immediately after the ball is thrown.

A toy parachute is falling through air. The air resistance F acting on the parachute is given by the expression

F = kv²

where v is the speed of the parachute and k is a constant.

The S.I. base units for F are kg m s⁻².

Show that the S.I. base units for k are kg m⁻¹.

The following items of data are collected for the parachute.

• v = 1.20 ± 0.12 m s⁻¹

• F = 4.00 ± 0.24 N

Calculate the absolute uncertainty in k. Write your answer to 2 significant figures.

absolute uncertainty in k =........ kg m⁻¹

A drone is a small remotely-controlled aircraft.

A drone is travelling horizontally in a cross-wind. The drone is travelling due north at a constant speed 9.0 m s⁻¹ relative to the air. The speed of the wind is 4.2 m s⁻¹. The direction of the wind is 130° from the north.

An incomplete vector diagram for determining the resultant velocity of the drone is shown below.

The vector diagram is drawn to scale.

Complete the vector diagram to show the resultant velocity of the drone.

Determine the magnitude of the resultant velocity v of the drone.

v =........ m s⁻¹

The diagram below shows an object of weight 7.5 N hung from the drone using a steel wire.

The drone is now hovering at a fixed position above the ground.

The wire has cross-sectional area 8.2 × 10⁻⁷ m² and original length 62 cm. The Young modulus of steel is 2.0 × 10¹¹ Pa. The wire obeys Hooke’s law.

Calculate the extension x of the wire.

The drone now moves vertically upwards. The velocity v against time t graph for the drone is shown below.

The tension in the wire at X is 7.5 N.

Describe and explain how the tension in the wire at Y and Z compares with 7.5 N.

Suggest why the graph does not pass through the origin.

The resistivity of graphite is .

Describe how the student can use the graph above, and an additional measuring instrument, to accurately determine . No calculations are required.

The diagram below shows a mat used for underfloor heating.

Each mat has resistance wire. The wire has cross-sectional area 6.7 × 10⁻⁸ m², total length 25 m and resistance 180 . Each mat dissipates 300 W when connected to the mains supply.

A total output power 1.2 kW is required for a room.

Calculate the number of mats required.

Calculate the resistivity of the material of the wire.

=........ m

A student connects a calibrated 10.0 resistor across a chemical cell of electromotive force (e.m.f.) 1.50 V. The student expects the current in the resistor to be 0.150 A.

Explain why the actual current will not be 0.150 A.

The diagram below shows part of an electrical circuit connected by the student.

The lamps are identical. The graph below shows the I -V characteristic of one of the lamps.

The potential difference (p.d.) across lamp A is 6.0 V.

Use the graph to determine the total resistance of the lamps.

Two progressive waves A and B meet at a point P. The displacement x against time t graphs for A and B at the point P are shown below.

Explain how the graphs show that the waves are coherent.

Determine the frequency f of the wave A.

The intensity of wave A is I₀.

Determine the intensity of wave B in terms of I₀.

Determine the resultant displacement at the point P at time t = 2.5 ms.

The diagram below shows two coherent sources of radio waves X and Y.

The diagram is not drawn to scale.

The radio waves are in phase at X and Y. A car moves at a constant speed along the line PQ. The line PQ is parallel to line XY. The separation between X and Y is 120 m. The perpendicular distance between lines PQ and XY is 2400 m.

The intensity against time graph below shows the variation of the intensity of the radio waves at the position of the moving car.

State the principle of superposition of waves.

Explain the maxima and minima in the variation of the intensity.

The time between adjacent maxima is 200 s. The speed of the car is 18 m s⁻¹.

Calculate the wavelength of the radio waves.

Electromagnetic radiation, with a range of wavelengths, is incident on a metal. Electrons are removed from the metal due to the photoelectric effect.

The maximum kinetic energy KE_max of the emitted electrons against wavelength graph is shown below.

Explain the shape of the graph in terms of quantum physics.

Some lasers are used in eye surgery. One such laser emits a beam of light of wavelength 490 nm and power 230 mW.

Calculate

the energy of each photon of light from the laser.

the number of photons of light emitted in each second.