2009 - WAEC Physics Past Questions and Answers - page 2
11
A body of mass 5kg movimg with a velocity of 30ms-1 due east is suddenly hit by another body and changes its velocity to 50ms-1 in the same direction. Calculate the magnitude of the impulse received.
A
100Ns
B
150Ns
C
250Ns
D
400Ns
12
Electric energy is measured in
A
ampere
B
coulomb
C
kilowatt-hour
D
kilowatt
correct option: c
Users' Answers & Comments13
A stone of mass 0.5kg is dropped from a height of 12m. Calculate its maximum kinetic energy. [g = 10ms-1]
A
3.0J
B
6.0J
C
30.0j
D
60.0J
14
A machine of efficiency 80% is used to lift a box. If the effort applied by the machine is twice the weight of the box. Calculate the velocity ratio of the machine
A
0.50
B
0.63
C
0.80
D
1.60
correct option: b
Y = \(\frac{M.A}{V.R} \times \frac{100}{1}\)
= \(\frac{\frac{1}{2}}{V.R} \times \frac{100}{1}\)
V.R = 0.625
Users' Answers & Comments= \(\frac{\frac{1}{2}}{V.R} \times \frac{100}{1}\)
V.R = 0.625
15
A faulty thermometer registers 102.5oC t 100oC. If the thermometer has no zero hour, what will it register at 55oC?
A
54.6oC
B
55.0oC
C
56.0oC
D
56.4oC
16
A rod of initial lenght 2m at a temperature of 25oC is heated to 80oC. Calculate the increase in length of the rod if its linear expansivity is 4.0 x 10-3K-1
A
0.26m
B
0.44m
C
0.53m
D
0.84m
correct option: b
\(l_2 - l_1 = \alpha l_1 (\theta_2 - \theta_1) = 4.0 \times 10^{-3} \times 2(80 - 25)\)
= 0.44m
Users' Answers & Comments= 0.44m
17
as a bicycle Tyre was being pumped up, it was noticed that contrary to Boyle's law the volume increased as the pressure increased. The best explanation of this is that Boyle's law is only true for
A
ideal gases
B
a fixed mass of gas
C
a mixture of gases
D
a gas at variable temperature
correct option: a
Users' Answers & Comments18
It takes 4 minutes to boil a quantity of water using an electrical heating coil. How long will it take to boil the same quantity of water using the same coil if the current is doubled? [Neglect any external heat losses]
A
8 minutes
B
4 minutes
C
2 minutes
D
1 minute
correct option: c
Users' Answers & Comments19
When table salt is added to ice, the melting point of the ice
A
is raised
B
is lowered
C
remains unchanged
D
is first raised, then lowered
correct option: b
Users' Answers & Comments20
Which of the following is used to measure relative humidity?
A
hydrometer
B
barometer
C
hypsometer
D
hygrometer
correct option: d
Users' Answers & Comments