2007 - WAEC Physics Past Questions and Answers - page 5
41
Which of the following electromagnetic wave can be detected by its heating effect?
A
ultraviolet radiation
B
x-rays
C
gamma rays
D
infrared radiation
correct option: d
Users' Answers & Comments42
If a gas is excited by high voltage to produce a discharge and the light is examined in a spectrometer
A
an explosion is observed
B
the rainbow colours are seen
C
an emission spectrum is observed
D
dark lines are observed
correct option: c
Users' Answers & Comments43
The number of protons in an element increased by one after a radioactive decay. The element must have decay by emitting
A
a beta particle
B
an alpha particle
C
a gamma ray
D
a neutron
correct option: a
Users' Answers & Comments44
In a nuclear reactor, chain reactions result from the release of
A
electrons
B
photons
C
neutrons
D
protons
correct option: c
Users' Answers & Comments45
The correct sequence of energy transformation in the operation of an x-ray tube is i. X-rays ii. Kinetic energy of thermo electrons iii. Potential energy of the target atoms iv. Heat energy of the emitted electrons
A
iv, iii, ii, i
B
ii, iv, iii, i
C
iv, ii, iii, i
D
iii, iv, ii, i
correct option: a
Users' Answers & Comments46
There is always an uncertainty involved in any attempt to measure the position and momentum of an electron simultaneously. This statement is known as the
A
de Broglie's law
B
Heisenberg uncertainty principle
C
Franck-Hertz experimental law
D
wave-particle paradox
correct option: b
Users' Answers & Comments47
The diagram above illustrates three forces acting on an object at point O. If the object is in equilibrium, determine the magnitude of the force P.
A
10.5N
B
11.0N
C
17.3N
D
20.0N
48
Calculate the effective resistance between P and Q in the diagram above
A
0.75\(\Omega\)
B
4.00\(\Omega\)
C
5.00\(\Omega\)
D
7.00\(\Omega\)