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 1621–1635 of 5315 verified questions
Sort by:
Physics
WAEC / WASSCE 2014
Thermal Physics
An aluminum foil is placed across a beam of radiation from a radioactive source. Which of the following types of radiation will be stopped by it?
A
alpha and beta particles
B
alpha and gamma particles
C
beta and gamma particles
D
gamma particles only
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 #35783)
Physics
WAEC / WASSCE 2014
Modern Physics and Nuclear Physics
An element of nucleon number P and atomic number Q emits an alpha particle from its nucleus. The resultant numbers of the new element formed are respectively
A
P - 4 and Q + 2
B
P - 4 and Q - 2
C
P + 2 and Q + 2
D
P + 2 and Q - 2
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 #35784)
Physics
WAEC / WASSCE 2014
Mechanics and Properties of Matter
Solution
Two identical charges situated 20cm apart in vacuum repel each other with a force of 1.0N.Calculate the value of each other with a force of 1.0N. Calculate the value of each charge. [(14 \(\pi \varepsilon_o)^{-1}\) = 9 x 109Nm2C-2]
A
21\(\mu C\)
B
3.6\(\mu C\)
C
4.0\(\mu C\)
D
4.4\(\mu C\)
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
F = \(\frac{Q^2}{4 \pi \varepsilon_o r^2}\)
I = 9 x 109 x \(\frac{Q^2}{0.2^2}\)
Q = \(\sqrt{\frac{0.04}{9 \times 10^9}}\)
= 2.11 x 10-6
Source: Myschool Past Questions Archive (Record #35776)
Physics
WAEC / WASSCE 2014
Electricity and Magnetism
Diagram
Solution
In the circuit diagram above, E is a battery of negligible internal resistance. If its emf is 9.0V. Calculate the current in the circuit ``
Attached Figure / Diagram
A
1.8A
B
1.0A
C
0.8A
D
0.3A
medium Difficulty
Verified Correct Answer: Option B
Physical Principles & Numerical Solution
\(\frac{1}{r} = \frac{1}{r_1} + \frac{1}{r_2}\)
= \(\frac{1}{5} + \frac{1}{20}\)
= \(\frac{4 + 1}{20} = \frac{5}{20}\)
r = \(\frac{20}{5}\)
= 4\(\Omega\)
R = R1 + R2
= 5 + 4
= 9\(\Omega\)
but V = IR
I = \(\frac{V}{R} = \frac{9}{9}\)
= 1A
Source: Myschool Past Questions Archive (Record #35777)
Physics
WAEC / WASSCE 2014
Electricity and Magnetism
Solution
A wire of length 100 cm has a resistance of 10\(\Omega\). If its cross-sectional area is 0.005cm2, determine its resistivity
A
0.0005\(\Omega\)cm
B
0.0015\(\Omega\)cm
C
0.0016\(\Omega\)cm
D
0.0700\(\Omega\)cm
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
e = \(\frac{RA}{L} = \frac{10 \times 0.005}{100} = 0.0005\)
Source: Myschool Past Questions Archive (Record #35778)
Physics
WAEC / WASSCE 2014
Electricity and Magnetism
Solution
A transformer has 400 turns of wire in the primary coil and 40 turns in the secondary col. If the input voltage is 150 volts. Calculate the magnitude of the output voltage
A
150V
B
55V
C
36V
D
15V
medium Difficulty
Verified Correct Answer: Option D
Physical Principles & Numerical Solution
\(\frac{ES}{EP} = \frac{Ns}{Np} = \frac{Es}{150} = \frac{40}{400}\)
Es = \(\frac{150 \times 40}{400}\)
= 15V
Source: Myschool Past Questions Archive (Record #35779)
Physics
WAEC / WASSCE 2014
Thermal Physics
Diagram
The circuit above illustrates a standard resistor R, voltage source E and a lamp L connected in series. If the temperature of R is increased, the brightness of the lamp will
Attached Figure / Diagram
A
increase sharply
B
decrease slightly
C
remains the same
D
increase gradually
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 #35780)
Physics
WAEC / WASSCE 2014
Heat Energy & Temperature
Solution
You are provided with a potentiometer AB, a 102\(\Omega\) standard resistor R, a battery of emf 4.5V, a jockey J, and other necessary materials.
Connect a circuit as shown in the diagram above.
Close key K. Without J making contact with AB, read and record the ammeter reading I. Open the key.
Use the jockey to make contact with AB at the 20cm mark such that AJ = x = 20cm. Close the key, read and record the ammeter reading.
Evaluate x\(^{-1}\).
Repeat the procedure for values of x= 35cm, 45cm, 60cm, and 80cm respectively.
Tabulate your readings.
Plot a graph with x\(^{-1}\) on the vertical axis and \(l_i\) on the horizontal axis, starting both axes from the origin (0, 0).
Determine the slope, s, of the graph.
From your graph, determine the value \(l_o\) of \(I_1\) for which x\(^{-1}\)= 0.
Evaluate \(\frac{I_{o}}{I}\).
State two precautions taken to obtain accurate results.
(b)i. Define the emf of a battery.
ii. A cell X of emf 1.018V is balanced by a length of 50.0cm on a potentiometer wire. Another cell Y is balanced by a length of 75.0cm on the same wire. Calculate the emf of Y.
A
increase sharply
B
decrease slightly
C
remains the same
D
increase gradually
medium Difficulty
Verified Correct Answer: Option B
Physical Principles & Numerical Solution
Electricity
I = 0.36A
\(\frac{x}{cm}\)
\(\frac{I}{A}\)
\(\frac{X^{-1}}{cm^{-1}}\)
20.0
1.14
0.050
35.0
0.90
0.029
45.0
0.84
0.022
60.0
0.78
0.017
80.0
0.66
0.013
Slope (s) = \(\frac{\bigtriangleup {X}^{-1}}{\bigtriangleup {I}}\) = \(\frac{0.08-0.01}{1.68-0.644} = \frac{0.07}{1.036}\)
From the graph,
When X\(^{-1}\) = 0
\(I_0\) of \(I_1\) = 0.448A
x. Evaluate \(\frac{I_{0}}{I}\)
= \(\frac{0.448}{0.36}\) = 1.244
Precaution;
The key was opened when readings were not taken.
I ensured tight connections of the connecting wire
I avoided parallax errors when reading the potentiometer.
(bi) Define emf of a battery: The e.m.f of a cell is the potential difference across its terminals when it is in an open circuit. i.e. not Supplying current to an external circuit.
ii. A cell x emf is 1.018V.
Lengt\(h_1\) on the potentiometer x = 50.0cm
Lengt\(h_2\) on the potentiometer, y,= 75.0cm
A cell Y emf is?
Solution
By formula;
\(\frac{E_{1}}{E_{2}}\) = \(\frac{L_{2}}{L_{1}}\)
\(\frac{1.018}{E_{2}} = \frac{75.0}{50.0}\)
75.\(E_2\) = 1.018 x 50
\(E_2\) = \(\frac{1.018\times 50}{75}\)
\(E_2\) = 0.612V.
see graph above
Source: Official Exam / Past Question Archive
Physics
WAEC / WASSCE 2014
Heat Energy & Temperature
Solution
A particle is projected horizontally at 10 ms\(^{-2}\) from the top of a tower 20 M high. Calculate the horizontal distance travelled by the particle when it hits the level ground. [g= 10 ms\(^{-2}\)
medium Difficulty
Verified Correct Answer: Option
Physical Principles & Numerical Solution
R = U\(\sqrt{\frac{2H}{g}} = 10\sqrt{\frac{2 \times 20}{10}}\) = 20
Source: Myschool Past Questions Archive (Record #53061)
Physics
WAEC / WASSCE 2014
Mechanics and Properties of Matter
Solution
A tennis ball projected at an angle 0 attains a range R = 78. If the velocity imparted to the ball by the racket is 30 ms\(^{-1}\), calculate O. [ g = 10 ms\(^{-2}\)]
medium Difficulty
Verified Correct Answer: Option
Physical Principles & Numerical Solution
R = \(\frac{U^2 sin 2\theta}{g}\), 78 = \(\frac{30^2 sin 2\theta}{10}\)
\(sin2\theta = \frac{780}{900}\) = 0.8667, \(2\theta = sin^{-1}0.8667 = 60^o\)
\(\theta \frac{60^o}{2} = 30^o\)
Source: Myschool Past Questions Archive (Record #53062)
Physics
WAEC / WASSCE 2014
Electricity and Magnetism
Solution
An electron moves with a speed of 2.00 x 10\(^7\) ms\(^{-1}\) in an orbit in a uniform magnetic field of 1.20 x 10\(^{-3}\) T. Calculate the radius of the orbit. [Mass of an electron = 9.11 x 10\(^{-3}\) kg; charge on an electron = 1.61 x 10\(^{-19}\)C]
medium Difficulty
Verified Correct Answer: Option
Physical Principles & Numerical Solution
\(\frac{Mv^2}{r}\) = qvB
r = \(\frac{MV^2}{qVB} = \frac{9.11 \times 10^{31} \times (2.00 \times 10^7)^2}{1.61 \times 10^{-19} \times 2.00 \times 10^7 \times 1.2 \times 10^{-3}}\)
= 9.43 x 10\(^{-2}\)
Source: Myschool Past Questions Archive (Record #53064)
Physics
WAEC / WASSCE 2014
Mechanics and Properties of Matter
Solution
A metallic bar 50 cm long has a uniform cross-sectional area of 4.0 cm\(^2\). If a tensile force of 35 kN produces an extension of 0.25 mm, calculate the value of Young's modulus
medium Difficulty
Verified Correct Answer: Option
Physical Principles & Numerical Solution
E \(\frac{Fl}{Ae}\)
= \(\frac{35 \times 10^3 \times 50 \times 10^{-2}}{4 \times 10^{-4} \times 0.25 \times 10 ^{-3}}\)
= 1.75 x 10\(^{11}\)Nm\(^{-2}\)
Source: Myschool Past Questions Archive (Record #53065)
Physics
WAEC / WASSCE 2014
Mechanics and Properties of Matter
Solution
(a) Explain how a gas can be made to conduct electricity.
(b) Name the electric charge carriers in gases.
medium Difficulty
Verified Correct Answer: Option
Physical Principles & Numerical Solution
(a) Under very low pressure and very high voltage in at enclosed discharge tube ionized gas molecules or atom can conduct electricity.
(b) Electric charge carriers in gases are ions and electrons.
Source: Myschool Past Questions Archive (Record #53066)
Physics
WAEC / WASSCE 2014
Mechanics and Properties of Matter
Solution
The diagram above represents the graph of electron energy against the frequency of the radiation incident on a metal surface. Interpret the: (a) slope of the graph; (b) intercept, OC; (c) intercept, OK.
medium Difficulty
Verified Correct Answer: Option
Physical Principles & Numerical Solution
(a) Graph slope represents Planck's constant.
(b) Intercept OC represents work function of the metal.
(c) Intercept OK represents the threshold frequency F\(_o\) of the incident radiation
Source: Myschool Past Questions Archive (Record #53075)
Physics
WAEC / WASSCE 2014
Mechanics and Properties of Matter
Solution
(a) State two conditions under which photo-electrons can be emitted from the surface of a metal.
(b) List two particle characteristics of electromagnetic waves.
medium Difficulty
Verified Correct Answer: Option
Physical Principles & Numerical Solution
Conditions for photo-electrons emission are:
(i) the energy of the incident photons radiation mus', be greater than the work function of the metal.
(ii) the wavelength of incident radiation must be less than the threshold wavelength for metal surface.
(iii) the frequency of incident radiation must be greater than the threshold, frequency.
(b) Particle characteristics of electroniagnetic waves are:
(i) Thermionic emission
(ii) Photoelectric effect
(iii) Compton effect
(iv) Emission and absorption of incandescence light.
(v) Radiations from heated black bodies.
Source: Myschool Past Questions Archive (Record #53076)