2017 - WAEC Physics Past Questions and Answers - page 4
31
A battery of e.m.f 3.0V is connected across a potentiometer wire AB of length 10\(\Omega m^{-1}\) as illustrated in the diagram above. If the jockey J makes contact at the 30cm mark, determine the resistance of length AJ and voltage across AJ.
A
3.0\(\Omega\); 0.9V
B
3.0\(\Omega\); 3.0V
C
3.3\(\Omega\); 0.3V
D
3.3\(\Omega\); 9.0V
32
The main reason why a.c. is transmitted at very high voltage and low current is that
A
flows faster through the conductor
B
can be stepped down
C
is cheaper to generate
D
reduces heat loss
33
The inverse of the time required for a wave to complete one full cycle is called
A
wavelength
B
period
C
frequency
D
amplitude
34
Two bar magnets are placed near each other. Which of the following diagrams correctly illustrates the magnetic field pattern formed by the pair?
A
I
B
II
C
III
D
IV
35
The force per unit charge experienced at a point in a field is the
A
gravitational field strength
B
electric potential
C
electric field intensity
D
magnetic field strength
36
Which of the following objects is not a conductor of electricity?
A
The Earth
B
Human body
C
Iron rod
D
Dry wood
37
A circuit is set up as shown in the diagram above. When the key is closed, the ammeter reading will be
A
6A
B
4A
C
2A
D
1A
38
Which of the following statements is/ are correct?
I. Gravitational potential due to a mass at a point a distance r away is proportional to \(r^{2}\)
II. Gravitational field strength is a vector quantity
III. Gravitational intensity is proportional to the weight of a unit mass.
A
I, II and III
B
III only
C
II only
D
I only
39
The diagrams above illustrate electrical connections to the element of an electric pressing iron.In which of the connections is the fuse correctly fixed?
A
I
B
II
C
III
D
IV
40
A lamp rated 100W, 240V is lit for 5hours. Calculate the cost of lighting the lamp if 1kWh of electrical energy cost N5.
A
N2.50
B
N3.20
C
N6.50
D
N9.60
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