2000 - JAMB Physics Past Questions and Answers - page 5
41
An engineer intends to deviate a light ray from its path by 120o through reflection from a plane mirror. Calculate the angle of incidence
A
60o
B
40o
C
30o
D
20o
correct option: c
Angle of deviation = 180 - [i + v]
= 180 - 2i [since i = v]
∴ 120 = 180 - 2i
2i = 180 - 120
= 60
∴ i = 30o
Users' Answers & Comments= 180 - 2i [since i = v]
∴ 120 = 180 - 2i
2i = 180 - 120
= 60
∴ i = 30o
42
A
Alcohol, mercury and alcohol
B
Air, alcohol and mercury
C
Mercury, alcohol and mercury
D
Air, mercury and alcohol
correct option: a
Users' Answers & Comments43
A
2μC and 4μC
B
4μC and 2μC
C
100μC and 200μC
D
200μC and 100μC
correct option: c
Since capacitance C = Q/V, => Q = CV
∴ Qp = 5 x 10-b x 20
= 100 x 10-b or 100μC
Qp = 10 x 10-b x 70
= 200 x 10-b or 200μC
Correct option 100μC and 200μC
Users' Answers & Comments∴ Qp = 5 x 10-b x 20
= 100 x 10-b or 100μC
Qp = 10 x 10-b x 70
= 200 x 10-b or 200μC
Correct option 100μC and 200μC
44
A
red, green and blue
B
Green, red and blue
C
Yellow , blue and red
D
Blue , yellow and red
correct option: a
Users' Answers & Comments45
A
1V and 1/3V
B
1/3V and 1V
C
1/3V and 2/3V
D
1V and 2/3V
correct option: d
Effective resistance in the circuit
= 3 + 2 + 1 = 6Ω
Current through the I = E/(R+V)
∴I = 2/6
=> V1 = I x R1 2/6 x 3/1 = 1V
= V2 = I x R2 = 2/6 x 2/1 = 2/3V
∴ we have 1V and 2/3V
Users' Answers & Comments= 3 + 2 + 1 = 6Ω
Current through the I = E/(R+V)
∴I = 2/6
=> V1 = I x R1 2/6 x 3/1 = 1V
= V2 = I x R2 = 2/6 x 2/1 = 2/3V
∴ we have 1V and 2/3V
46
A
between P and Q
B
Q
C
S
D
P
correct option: d
Users' Answers & Comments47
A
P
B
Y
C
X
D
Q
correct option: d
Users' Answers & Comments48
A
0.58 A
B
3.00 A
C
4.00 A
D
6.67 A
correct option: c
Impedance Z =
√ R2 x X2
=
√ 302 x 402
∴Z =
√ 2500 = 50W
But current I = V/Z = 200/50 = 4.00 A
Users' Answers & Comments√ R2 x X2
=
√ 302 x 402
∴Z =
√ 2500 = 50W
But current I = V/Z = 200/50 = 4.00 A
49
A handbag containing some load weighing 162N is carried by two students each holding the handle of the bag next to him. If each handle is pulled \( 60^{\circ} \) to the vertical, find the force on each student's arm
A
81N
B
121N
C
162N
D
324N
correct option: c
Users' Answers & Comments