Question Library
Browse, filter, and study verified past examination questions with step-by-step mathematical reasoning.
Searching 18,000+ Questions...
Sifting topics, KaTeX formulas & verified solutions
Showing 2821–2835 of 13612 verified questions
Sort by:
Physics
WAEC / WASSCE 2018
Waves and Optics
Diagram
Solution
The lens illustrated above can best be described as a
Attached Figure / Diagram
A
converging meniscus
B
plano-convex
C
diverging meniscus
D
bi-convex
medium Difficulty
Verified Correct Answer: Option B
Physical Principles & Numerical Solution
The diagram is that of a plano-convex lens; a type of converging lens.
Source: Myschool Past Questions Archive (Record #49730)
Physics
WAEC / WASSCE 2018
Mechanics and Properties of Matter
Diagram
Solution
A bar AB is balanced horizontally on two knife edges as illustrated as in the diagram above. Determine the weight of the bar.
Attached Figure / Diagram
A
10.0N
B
20.0N
C
40.0N
D
50.0N
medium Difficulty
Verified Correct Answer: Option C
Physical Principles & Numerical Solution
Upward force = downward force = weight of the Bar
20N + 20N = Weight of the BAR
Therefore, the weight of the bar = 40N
Source: Myschool Past Questions Archive (Record #49769)
Physics
WAEC / WASSCE 2018
Waves and Optics
Solution
To obtain a virtual, erect and magnified image from a thin converging lens, an object must be placed
A
between the focus and the lens
B
at the focus
C
between the focal length and twice the focal length
D
beyond twice the focal length
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
When the object is placed between the optical centre of the lens and the focal length, the image formed is virtual, erect and magnified.
Source: Myschool Past Questions Archive (Record #49772)
Physics
WAEC / WASSCE 2018
Waves and Optics
Diagram
Solution
The diagram above represents a transverse travelling wave. Which two points are 180^\circ out of phase?
Attached Figure / Diagram
A
A and E
B
B and D
C
C and F
D
D and H
medium Difficulty
Verified Correct Answer: Option B
Physical Principles & Numerical Solution
This means that when one Point is at its highest point, the other is at its lowest point, resulting in a 180-degree phase difference.
Source: Myschool Past Questions Archive (Record #49775)
Physics
WAEC / WASSCE 2018
Mechanics and Properties of Matter
Solution
Two objects P and Q of masses 100kg and 20kg respectively are 1.2m apart on a horizontal surface. Calculate the net gravitational force acting on Q. \([G= 6.67 \times 10^{-11} Nm^{2}kg^{-2}]\)
A
\(1.11\times 10^{-7} N\) towards P
B
\(1.11\times 10^{-7} N\) towards Q
C
\(9.26\times 10^{-8} N\) towards P
D
\(9.26\times 10^{-8} N\) towards Q
medium Difficulty
Verified Correct Answer: Option C
Physical Principles & Numerical Solution
\(F= \frac{Gm_{1}m_{2}}{r^{2}}\)
\(m_{1} = 100kg\)
\(m_{2} = 20kg; r =1.2m\)
\(G= 6.67\times 10^{-11}\)
\(F = \frac{6.67\times 10^{-11}\times 100\times 20}{(1.2)^{2}} = 9.26\times 10^{-8}\)
Gravitational force is always attractive. Therefore, the net force acting on object Q will pull it directly towards the larger mass, P.
Source: Myschool Past Questions Archive (Record #49788)
Physics
WAEC / WASSCE 2018
Mechanics and Properties of Matter
Solution
The primary of a transformer has 100 turns and its secondary has 200 turns. If the voltage at the primary is 100V, determine the voltage at the secondary.
A
50V
B
100V
C
200V
D
400V
medium Difficulty
Verified Correct Answer: Option C
Physical Principles & Numerical Solution
The ideal transformer (either step-up or step-down) works with the equation:
\(\frac{V_{s}}{V_{p}} = \frac{N_{s}}{N_{p}} = \frac{I_{p}}{I_{s}}\)
where \(V_{s}\) and \(V_{p}\) are the voltages applied to the secondary and the primary respectively
\(N_{s}\) and \(N_{p}\) are the number of turns on the secondary and primary coils respectively
\(I_{p}\) and \(I_{s}\) are the currents flowing in the primary and secondary coils respectively.
\(\frac{V_{s}}{100} = \frac{200}{100}\)
\(V_{s} = \frac{200\times 100}{100} = 200V\)
Source: Myschool Past Questions Archive (Record #49794)
Physics
WAEC / WASSCE 2018
Mechanics and Properties of Matter
Diagram
Solution
In the diagram illustrated a block of mass M is at rest on a plane inclined at an angle \(\theta\) to the horizontal. As \(\theta\) increases, the velocity ratio of the plane
Attached Figure / Diagram
A
increases
B
decreases
C
remain the same
D
decreases and later increases
medium Difficulty
Verified Correct Answer: Option B
Physical Principles & Numerical Solution
The velocity ratio and therefore, the mechanical advantage of an inclined plane system increases as \(\theta\) decreases and vice-versa.
Source: Myschool Past Questions Archive (Record #49797)
Physics
WAEC / WASSCE 2018
Mechanics and Properties of Matter
Solution
When the speed of a car is halved, its kinetic energy is
A
doubled
B
quartered
C
halved
D
quadrupled
medium Difficulty
Verified Correct Answer: Option B
Physical Principles & Numerical Solution
Given \(K_{1}\) = \(\frac{mv^{2}}{2}\).
When v is halved, we have
\(K_{2}\) = \(\frac{m\times (\frac{v}{2})^{2}}{2}\)
= \(\frac{K_{1}}{4}\)
Hence, the initial kinetic energy is quartered.
Source: Myschool Past Questions Archive (Record #49798)
Physics
WAEC / WASSCE 2018
Waves and Optics
Solution
A wire of length 400cm is stretched between two fixed points. When plucked, its fundamental frequency is 150Hz. Calculate the speed of the wave produced.
A
250\(ms^{-1}\)
B
625\(ms^{-1}\)
C
1200\(ms^{-1}\)
D
1500\(ms^{-1}\)
medium Difficulty
Verified Correct Answer: Option C
Physical Principles & Numerical Solution
The fundamental frequency \((f_{0})\) = \(\frac{v}{2l}\)
\(f_{0} = 150Hz; l =400cm = 4m\)
\(150 = \frac{v}{2\times 4}\)
\(v = 150 \times 8 = 1200ms^{-1}\)
Source: Myschool Past Questions Archive (Record #49800)
Physics
WAEC / WASSCE 2018
Waves and Optics
Diagram
Solution
The diagram above illustrates a waveform. Determine the number of wavelengths in it
Attached Figure / Diagram
A
4
B
3\(\frac{1}{2}\)
C
2\(\frac{1}{2}\)
D
2
medium Difficulty
Verified Correct Answer: Option C
Physical Principles & Numerical Solution
Number of wavelengths = Number of oscillations
Number of wavelengths = \(\frac{1}{4} + \frac{1}{2} + \frac{1}{2} + \frac{1}{2} + \frac{1}{2} +\frac{1}{4}\) = 2\(\frac{1}{2}\)
Source: Myschool Past Questions Archive (Record #49804)
Physics
WAEC / WASSCE 2018
Electricity and Magnetism
A resistor with fixed resistance value is called a
A
resistance box
B
standard resistor
C
shunt resistor
D
multiplier resistor
medium Difficulty
Verified Correct Answer: Option B
Physical Principles & Numerical Solution
No expanded working has been attached for this question yet. The verified answer is Option B.
Source: Myschool Past Questions Archive (Record #49808)
Physics
WAEC / WASSCE 2018
Heat Energy & Temperature
Which of the following statements is not an advantage of an alkaline accumulator?
A
The electrolyte does not need attention
B
It can be recharged
C
It has low internal resistance
D
It has a much longer life than lead-acid accumulator
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
No expanded working has been attached for this question yet. The verified answer is Option A.
Source: Myschool Past Questions Archive (Record #49817)
Physics
WAEC / WASSCE 2018
Heat Energy & Temperature
Diagram
The diagram above illustrates the wire connections to a three-pin plug. The wires P, Q and R respectively are:
Attached Figure / Diagram
A
live, neutral and earth
B
neutral, earth and live
C
earth, live and neutral
D
earth, neutral and live
medium Difficulty
Verified Correct Answer: Option B
Physical Principles & Numerical Solution
No expanded working has been attached for this question yet. The verified answer is Option B.
Source: Myschool Past Questions Archive (Record #49823)
Physics
WAEC / WASSCE 2018
Mechanics and Properties of Matter
Solution
Which of the following statements about parallel plate capacitors is/are correct?
I. Capacitance of the capacitor is inversely proportional to the distance between the plates
II. Capacitors can filter a.c signals from d.c
III. Capacitors can store charges
A
I only
B
I and II only
C
II and III only
D
I, II and III
medium Difficulty
Verified Correct Answer: Option D
Physical Principles & Numerical Solution
Capacitors pass AC but block DC signals (when charged up to the applied DC voltage), they are often used to separate the AC and DC components of a signal. Capacitors are also primarily used to store energy.
Source: Myschool Past Questions Archive (Record #49843)
Physics
WAEC / WASSCE 2018
Heat Energy & Temperature
Diagram
Solution
The circuit contains three ammeters A1, A2 and A3 with readings of A2 and A3 shown as indicated in the diagram. Determine the reading of A1.
Attached Figure / Diagram
A
2A
B
3A
C
5A
D
8A
medium Difficulty
Verified Correct Answer: Option B
Physical Principles & Numerical Solution
Ammeters are connected in series so,
A3= A2 + A1
A1 = A3 - A1
= 5A - 2A
= 3A
Source: Myschool Past Questions Archive (Record #49857)