JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
JD SCIENCE · ANSWERS · www.jdscience.co.uk
Eduqas A-Level Physics (A420)
A-Level Physics
Answer sheet

Fields and particles

Time guide: — · Questions: 32 · Total marks: 104
Written in Eduqas A-Level style. Show working and include units.

Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.

1.
State what is meant by Newton's law of gravitation.
[1 mark]
  • F = Gm₁m₂/r²
2.
State what is meant by gravitational field strength.
[1 mark]
  • g = F/m = GM/r²
3.
State what is meant by gravitational potential.
[1 mark]
  • V = −GM/r
4.
State what is meant by Coulomb's law.
[1 mark]
  • F = kQq/r²
5.
State what is meant by electric field strength.
[1 mark]
  • E = F/Q = kQ/r²
6.
State what is meant by capacitance.
[1 mark]
  • C = Q/V
7.
State what is meant by magnetic flux.
[1 mark]
  • Φ = BA cosθ
8.
State what is meant by Faraday and Lenz.
[1 mark]
  • ε = −N dΦ/dt
9.
State what is meant by a charged particle in a B field.
[1 mark]
  • F=BQv, circular path
10.
State what is meant by orbital motion of satellites.
[1 mark]
  • gravity = mv²/r
11.
Jac is asked about Newton's law of gravitation in a Eduqas Physics paper.
(a) [2 marks]
  • always attractive
(b) [3 marks]
  • inverse square
12.
Jac is asked about gravitational field strength in a Eduqas Physics paper.
(a) [2 marks]
  • N kg⁻¹
(b) [3 marks]
  • equals free-fall acceleration
13.
Jac is asked about gravitational potential in a Eduqas Physics paper.
(a) [2 marks]
  • work done per kg from infinity
(b) [3 marks]
  • equipotentials
14.
Jac is asked about Coulomb's law in a Eduqas Physics paper.
(a) [2 marks]
  • attract or repel
(b) [3 marks]
  • same inverse-square idea
15.
Jac is asked about electric field strength in a Eduqas Physics paper.
(a) [2 marks]
  • uniform field E=V/d
(b) [3 marks]
  • between plates
16.
Jac is asked about capacitance in a Eduqas Physics paper.
(a) [2 marks]
  • parallel plate C=εA/d
(b) [3 marks]
  • energy ½QV
17.
g=GM/r². M=6.0×10²⁴, r=6.4×10⁶, G=6.67×10⁻¹¹
[3 marks]
  • Final answer: 9.8 N kg⁻¹
18.
E=V/d. 12 V, 4.0 mm
[3 marks]
  • Final answer: 3000 V m⁻¹
19.
C=Q/V. 6.0 µC, 3.0 V
[3 marks]
  • Final answer: 2.0 µF
20.
½QV for those values
[3 marks]
  • Final answer: 9.0 µJ
21.
F=BQv. B=0.20, Q=1.6×10⁻¹⁹, v=3.0×10⁶
[3 marks]
  • Final answer: 9.6 × 10⁻¹⁴ N
22.
ε=NΔΦ/Δt. N=50, ΔΦ=0.040, Δt=0.10
[3 marks]
  • Final answer: 20 V
23.
Jac carries out a Eduqas-style required practical linked to gravitational, electric and magnetic fields. This is a typical Eduqas required-practical style question.
(a) [2 marks]
  • Independent: the independent variable for this topic
  • Dependent: the measured outcome
(b) [2 marks]
  • keep all other variables constant
  • so the test is fair / only one variable is changed
(c) [2 marks]
  • repeat and calculate a mean / use a tighter method
24.
Jac carries out collecting valid data for gravitational, electric and magnetic fields. This is a typical Eduqas required-practical style question.
(a) [2 marks]
  • Independent: a chosen factor
  • Dependent: a quantitative measurement
(b) [2 marks]
  • calibrated instrument
  • so the test is fair / only one variable is changed
(c) [2 marks]
  • systematic error from zero error
25.
Jac carries out drawing a graph for gravitational, electric and magnetic fields. This is a typical Eduqas required-practical style question.
(a) [2 marks]
  • Independent: x-variable
  • Dependent: y-variable
(b) [2 marks]
  • same scale / same apparatus
  • so the test is fair / only one variable is changed
(c) [2 marks]
  • not drawing a line of best fit through the trend
26.
Jac carries out evaluating a method about gravitational, electric and magnetic fields. This is a typical Eduqas required-practical style question.
(a) [2 marks]
  • Independent: method change
  • Dependent: precision / accuracy
(b) [2 marks]
  • same sample size
  • so the test is fair / only one variable is changed
(c) [2 marks]
  • too few repeats
27.
Compare Newton's law of gravitation with gravitational field strength.
[4 marks]
  • F = Gm₁m₂/r²
  • g = F/m = GM/r²
  • give one linked difference
28.
Compare gravitational field strength with gravitational potential.
[4 marks]
  • g = F/m = GM/r²
  • V = −GM/r
  • give one linked difference
29.
Compare gravitational potential with Coulomb's law.
[4 marks]
  • V = −GM/r
  • F = kQq/r²
  • give one linked difference
30.
Compare Coulomb's law with electric field strength.
[4 marks]
  • F = kQq/r²
  • E = F/Q = kQ/r²
  • give one linked difference
31.
Apply your knowledge of magnetic flux to this situation: weber
[3 marks]
  • weber
32.
Apply your knowledge of Faraday and Lenz to this situation: opposes the change
[3 marks]
  • opposes the change