theonlinephysicstutor.com
Mark schemes
A
1 [1]
C
2 [1]
B
3 [1]
A
4 [1]
B
5 [1]
B
6 [1]
C
7 [1]
D
8 [1]
(a) w = λD/s
9
C1
correct substitution – condone wrong powers of ten
C1
cao 11(.3) mm or equivalent; unit required
A1
3
(b) same frequency or wavelength
C1
constant phase (relationship)
A1
2
[5]
@TOPhysicsTutor facebook.com/TheOnlinePhysicsTutor
Page 27 of 41
, theonlinephysicstutor.com
(a) λ = yd/D
10
C1
substitution correct: condone
powers of 10
C1
5.6 × 107 m
A1
3
(b) waves arrive out of phase (with each other)
B1
path difference is 1.5λ
B1
idea of cancellation/destructive interference/negative
interference destruction
B1
3
[6]
(a) constant phase relationship (1) (1)
11 [or same frequency (wavelength) (1) and same phase difference (1)]
2
(b) S1R = 15cm on diagram (1) =75cm ∴ 30 waves (1)
S2R = 16cm on diagram (1) = 80cm ∴ 32 waves (1)
2 whole waves difference so in phase at R (1) maximum (1)
max 5
(c) (falls then rises to) maximum at Q (1)
(then falls and rises to) maximum at P (1)
2
(d) = = 1.2 × 1010 Hz (or 12 GHz) (1)
1
[10]
@TOPhysicsTutor facebook.com/TheOnlinePhysicsTutor
Page 28 of 41
Mark schemes
A
1 [1]
C
2 [1]
B
3 [1]
A
4 [1]
B
5 [1]
B
6 [1]
C
7 [1]
D
8 [1]
(a) w = λD/s
9
C1
correct substitution – condone wrong powers of ten
C1
cao 11(.3) mm or equivalent; unit required
A1
3
(b) same frequency or wavelength
C1
constant phase (relationship)
A1
2
[5]
@TOPhysicsTutor facebook.com/TheOnlinePhysicsTutor
Page 27 of 41
, theonlinephysicstutor.com
(a) λ = yd/D
10
C1
substitution correct: condone
powers of 10
C1
5.6 × 107 m
A1
3
(b) waves arrive out of phase (with each other)
B1
path difference is 1.5λ
B1
idea of cancellation/destructive interference/negative
interference destruction
B1
3
[6]
(a) constant phase relationship (1) (1)
11 [or same frequency (wavelength) (1) and same phase difference (1)]
2
(b) S1R = 15cm on diagram (1) =75cm ∴ 30 waves (1)
S2R = 16cm on diagram (1) = 80cm ∴ 32 waves (1)
2 whole waves difference so in phase at R (1) maximum (1)
max 5
(c) (falls then rises to) maximum at Q (1)
(then falls and rises to) maximum at P (1)
2
(d) = = 1.2 × 1010 Hz (or 12 GHz) (1)
1
[10]
@TOPhysicsTutor facebook.com/TheOnlinePhysicsTutor
Page 28 of 41
