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 91–105 of 557 verified questions
Sort by:
Physics
UTME / JAMB 2017
Electricity and Magnetism
Which of the following is true of an electrical charge?
A
Positive charge means deficit electrons
B
Negative charge means excess of electrons
C
electric current means movement of electrons
D
All of the above
medium Difficulty
Verified Correct Answer: Option D
Physical Principles & Numerical Solution
No expanded working has been attached for this question yet. The verified answer is Option D.
Source: Myschool Past Questions Archive (Record #47377)
Physics
UTME / JAMB 2017
Electricity and Magnetism
Which of the following is not true of an electrical charge?
A
Negative charge means deficit electrons
B
Negative charge means excess of electrons
C
electric current means movement of electrons
D
All of the above
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 #47379)
Physics
WAEC / WASSCE 2017
Electricity and Magnetism
Diagram
Two bar magnets are placed near each other. Which of the following diagrams correctly illustrates the magnetic field pattern formed by the pair?
Attached Figure / Diagram
A
I
B
II
C
III
D
IV
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 #50034)
Physics
WAEC / WASSCE 2017
Electricity and Magnetism
Solution
Which of the following objects is not a conductor of electricity?
A
The Earth
B
Human body
C
Iron rod
D
Dry wood
medium Difficulty
Verified Correct Answer: Option D
Physical Principles & Numerical Solution
Dry wood is rather an insulator and not a conductor.
Source: Myschool Past Questions Archive (Record #50038)
Physics
WAEC / WASSCE 2017
Electricity and Magnetism
Diagram
Solution
A circuit is set up as shown in the diagram above. When the key is closed, the ammeter reading will be
Attached Figure / Diagram
A
6A
B
4A
C
2A
D
1A
medium Difficulty
Verified Correct Answer: Option C
Physical Principles & Numerical Solution
The resistors are connected both in parallel and series. To calculate the total resistance, we have:
For the parallel connection: \(\frac{1}{R} = \frac{1}{1} + \frac{1}{1}\)
\(\frac{1}{R} = 2 \implies R = 0.5\Omega\)
For the series connection: \(R_{total} = (1 + 0.5)\Omega = 1.5\Omega\)
Recall, \(V=IR\)
\(3 = 1.5I \implies I = \frac{3}{1.5} =2A\)
Source: Myschool Past Questions Archive (Record #50045)
Physics
WAEC / WASSCE 2017
Electricity and Magnetism
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
medium Difficulty
Verified Correct Answer: Option D
Physical Principles & Numerical Solution
No expanded working has been attached for this question yet. The verified answer is Option D.
Source: Myschool Past Questions Archive (Record #50089)
Physics
WAEC / WASSCE 2017
Electricity and Magnetism
The opposition offered to an alternating current in a C-R series circuit is known as
A
impedance
B
resistance
C
reactance
D
friction
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 #50093)
Physics
WAEC / WASSCE 2017
Electricity and Magnetism
Diagram
The diagrams above illustrate electrical connections to the element of an electric pressing iron.In which of the connections is the fuse correctly fixed?
Attached Figure / Diagram
A
I
B
II
C
III
D
IV
medium Difficulty
Verified Correct Answer: Option C
Physical Principles & Numerical Solution
No expanded working has been attached for this question yet. The verified answer is Option C.
Source: Myschool Past Questions Archive (Record #50072)
Physics
WAEC / WASSCE 2017
Electricity and Magnetism
Diagram
Solution
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.
Attached Figure / Diagram
A
3.0\(\Omega\); 0.9V
B
3.0\(\Omega\); 3.0V
C
3.3\(\Omega\); 0.3V
D
3.3\(\Omega\); 9.0V
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
E = 3.0V; \(\frac{R}{l} = 10\Omega m^{-1}\)
l = 30cm = 0.3m; R = \(10\Omega m^{-1} \times 0.3m = 3\Omega\)
\(\frac{E}{V} = \frac{l_{1}}{l_{2}} \implies \frac{3}{V} = \frac{1}{0.3}\)
= \(\frac{3\times 0.3}{1} = 0.9V\)
Source: Myschool Past Questions Archive (Record #50088)
Physics
WAEC / WASSCE 2017
Electricity and Magnetism
Solution
List three advantages of p - n junetion diode over diode valve.
medium Difficulty
Verified Correct Answer: Option
Physical Principles & Numerical Solution
The advantages of P – n; junction diode over diode valves are:
(i) It is not bulky
(ii) It does not need time to warm up
(iii) It is cheaper to manufacture in large quantities.
(iv) It needs low voltage to operate.
Source: Myschool Past Questions Archive (Record #52887)
Physics
WAEC / WASSCE 2017
Electricity and Magnetism
Solution
(i) What is dielectric?
(ii) A parallel plate capacitor consists of two plates each of area 9.6 x 10\(^{-2}\)m\(^2\), separated by a dielectric of thickness 2.25 x 10\(^{-3}\) and dielectric constant 900. Calculate the capacitance of the capacitor. [ \(\varepsilon_o\) = permittivity of free space = 8.85 x 10\(^{-12}\)Fm\(^{-1}\)]
(b) (i) Which of the following devices has a higher resistance; an ammeter or a voltmeter? Give a reason for your answer.
(ii)
The resistance of the voltmeter in the circuit diagram illustrated above is 800\(\Omega\), Calculate the voltmeter reading.
(c)
A battery of negligible internal resistance is connected to a set of resistors as illustrated in the circuit diagram above. Determine the equivalent resistance of the circuit.
medium Difficulty
Verified Correct Answer: Option
Physical Principles & Numerical Solution
(a)(i) A dielectric is an insulating material (solid, liquid or gas) separating the two plates of a capacitor.
(ii) Using C = \(\frac{\xi_1.\xi_oA}{d} = \frac{900 \times 8.85 \times 10^{-12} \times 9.6 \times 10^{-3}}{2.25 \times 10^{-4}}\)
= 3.4 x 10\(^{-7}\)
(b)(i) A voltmeter has a higher resistance. Reason: A voltmeter is connected inparallel in a circuit to allow passage of minimal current through it; hence the circuit current is not significantly affected.
(ii)
\(\frac{1}{R_1} = \frac{1}{400} + \frac{1}{400}\) \(R_1 = 200\Omega\)
\(\frac{1}{R_2} = \frac{1}{800} + \frac{1}{800}\) \(R_1 = 400\Omega\)
RT= 200 + 400 = 600\(\Omega\)
I = \(\frac{V_T}{R_T} = \frac{6}{600}\) = 0.01A
Voltmeter reading
= Pd across R\(_2\)
= 0.01A
Voltmeter reading = Pd across R\(_2\)
= 0.01 x 400 = 4v
(c)
\(\frac{1}{R_p} = \frac{1}{2} + \frac{1}{2} = \frac{1 + 1}{2} = \frac{2}{2}\)
Note: This catadation is for the two resistors in parallel.
R\(_T = 2 + 1 + 2 = 5\Omega\)
Source: Myschool Past Questions Archive (Record #52894)
Physics
WAEC / WASSCE 2017
Electricity and Magnetism
Diagram
Solution
You are provided with cells, a potentiometer, an ammeter, a voltmeter, a bulb, a key, a jockey, and other necessary materials.
i. Measure and record the e.m.f E of the battery.
ii. Set up a circuit as shown in the diagram above.
iii. Close the key K and use the jockey to make a firm.
iii. Contact at J on the potentiometer wire such that PJ = x= 10cm.
iv. Take and record the voltmeter reading V and the () Corresponding ammeter reading.
v. Evalute log V and log I.
vi. Repeat the procedure for five other values of x = 20 cm, 30 cm, 40 cm, 50 cm, and 60 cm.
vii. Tabulate your readings.
viii. Plot a graph with log I on the vertical axis and log V on the horizontal axis.
ix. Determine the slope s, of the graph.
x. Determine the intercept, c, on the vertical axis.
xi. State two precautions taken to ensure accurate results.
(b)i. How is the brightness of the bulb affected as x increases?
ii. List two electrical devices whose actions do not obey Ohm's law.
Attached Figure / Diagram
medium Difficulty
Verified Correct Answer: Option
Physical Principles & Numerical Solution
S/N
I/A
V/V
LogV/V
LogI/A
1.0
0.10
0.30
-0.552
-1.000
2.0
0.15
0.50
-0.301
-0.823
3.0
0.20
0.70
-0.154
-0.698
4.0
0.25
0.80
-0.096
0.602
5.0
0.30
0.90
-0.045
0.522[
Slopes S = \(\frac{\bigtriangleup \text{logI}}{\bigtriangleup \text{logV}}\) = \(\frac{\text{logl}_{2}} {\text{logV}_{2}}\) - \(\frac{\text{logl}_{1}}{\text{logV}_{2}}\)
S = \(\frac{-1.00 - (-0.70)}{-0.15 - (0.50)}\) = \(\frac{0.30}{0.10}\)
S= 3
PRECUATIONS
1. avoided parallax error when reading ammeter and voltmeter
2. opened the key when readings are not being taken to ensure that the cells do not run down.
3. ensured that the jockey is not dragged along the potentiometer wire.
(b)i. As x increases, the brightness of the bulb increases. As x increases, voltage and current through the bulb also increases, hence brightness increases
ii. Electrical devices whose action does not obey ohm's law. They are: Diode, Capacitor, Transistor, Thermistor and Thyristor.
SEE GRAPH ABOVE
Source: Myschool Past Questions Archive (Record #59926)
Physics
UTME / JAMB 2016
Electricity and Magnetism
A charged particle is moving in a uniform magnetic field. if the direction of motion of the charged particle is parallel to the magnetic field, the path of the charge will
A
Be a straight line
B
Curve inwards
C
Be a parabola
D
Curve outwards
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 #44661)
Physics
UTME / JAMB 2016
Electricity and Magnetism
Solution
Which of the following does Not use magnetic effect of current to function?
A
Lead acid accumulator
B
An electric bell
C
A moving coil galvanometer
D
A telephone receiver
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
Lead acid accumulator does not use the magnet effect of current. It is an electrochemical cell that produces current as a result of a chemical reaction
Source: Myschool Past Questions Archive (Record #44713)
Physics
UTME / JAMB 2016
Electricity and Magnetism
Solution
Which of the following instruments can be used to measure current in an a.c circuit?
A
Hot wire ammeter
B
Moving coil ammeter
C
Tangent galvanometer
D
Moving coil galvanometer
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
A hot wire ammeter measures current by detecting the heating effect produced when current passes through a thin wire, with the amount of heat generated being directly proportional to the current flow.
Source: Myschool Past Questions Archive (Record #44727)