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 6241–6255 of 14893 verified questions
Sort by:
Physics
UTME / JAMB 2008
Atomic, Quantum, Nuclear Physics & Electronics
Solution
Caesium has a work function of 3 x 10\(^{-19}\)J. The maximum energy of liberated electrons when it is illuminated by light of frequency 6.7 x 10\(^{14}\)
HZ is? [h = 6.6 x 10\(^{-34}\)Js]
A
1.42 x 10-19J
B
3.00 x 10-19J
C
4.42 x 1010-19J
D
7.42 x 10-19J
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
Max kinetic energy = Energy of incident electron - work function. EK = hf - w
= 6.6 x 10-34 x 6.7 x 1014 - 3 x 10-19
= 4.422 x 10-19 - 3 x 10-19
= 1.422 x 10-19J
Source: WAEC / JAMB / NECO Classroom Archive (Record #14081)
Physics
UTME / JAMB 2008
Atomic, Quantum, Nuclear Physics & Electronics
Solution
If electron are accelerated from rest through a potential difference of 10kv, what is the wavelength of the associated electron?
[m = 9.1 x 10\(^{-31}\)kg, e = 1.6 x 10\(^{-19}\)C, h = 6.6 x 10\(^{-34}\)js]
A
1.22 x 10-11m
B
3.87 x 10-10m
C
2.27 x 1011m
D
2.27 x 1014m
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
\(\lambda\) = \(\frac{h}{\sqrt{2evm}}\)
= \(\frac{6.6 \times 10^{34}}{\sqrt{ 2 \times 1.6 \times 10^{-19} \times 10000 \times 9.1 \times 10^{-31}}}\)
= 1.223 x 10\(^{-11}\)m
Source: WAEC / JAMB / NECO Classroom Archive (Record #14493)
Physics
UTME / JAMB 2008
Atomic, Quantum, Nuclear Physics & Electronics
Solution
zener diode is used for?
A
current amplification
B
power amplification
C
voltage regulation
D
energy conversion
medium Difficulty
Verified Correct Answer: Option C
Physical Principles & Numerical Solution
Zener diode is useful in stabilized power supply i.e to keep steady the voltage of a power supply.
Source: WAEC / JAMB / NECO Classroom Archive (Record #14083)
Physics
UTME / JAMB 2008
Atomic, Quantum, Nuclear Physics & Electronics
Solution
When a pure semiconductor is heated, its resistance?
A
increases
B
decreases
C
remains the same
D
increases and then decreases
medium Difficulty
Verified Correct Answer: Option B
Physical Principles & Numerical Solution
Heating a pure semiconductor increases the mobility of electrons and holes and hence the conductivity. thus, the resistance decreases on heating
Source: WAEC / JAMB / NECO Classroom Archive (Record #14085)
Physics
UTME / JAMB 2008
Atomic, Quantum, Nuclear Physics & Electronics
Solution
I. for current amplification.
II. for voltage stabilization.
III. for power amplification.
IV. as a switch.
which of the above are the uses of transistor?
A
I,II,III and IV
B
I,III, and IV only
C
I, II and III only
D
I,II and IV only
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
Transistor is used for amplification of current, power', voltage stabilization and as a switch in logic gates.
Source: WAEC / JAMB / NECO Classroom Archive (Record #14089)
Physics
UTME / JAMB 2008
Reflection, Refraction & Dispersion of Light
Solution
I. Total internal reflection of light.
II. Conservation of light energy.
III. Relative motion of the earth, sun and moon.
IV. Rectilinear propagation of light.
which of the above is a phenomenon of total solar eclipse?
A
I and IV only
B
II and IV only
C
I and III only
D
III and IV only
medium Difficulty
Verified Correct Answer: Option D
Physical Principles & Numerical Solution
Due to rectilinear propagation of light we have ecslipse which occur as a result relative motion of the earth, sun and moon
Source: WAEC / JAMB / NECO Classroom Archive (Record #14047)
Physics
UTME / JAMB 2008
Reflection, Refraction & Dispersion of Light
Solution
An object of height 4cm is placed in front of a cuboid pinhole camera of size 6 cm. if the image formed is 2 cm high, how far is the object from the pinhole?
A
3.0 cm
B
8.0 cm
C
12.0 cm
D
16.0 cm
medium Difficulty
Verified Correct Answer: Option C
Physical Principles & Numerical Solution
Magnification = \(\frac{\text{image height}}{\text{object height}}
= \frac{\text{length camera}}{\text{object distance from pin-hole}}\)
∴\(\frac{2}{4} = \frac{6}{X}\)
X = \(\frac{4 \times 6}{2}\) = 12 cm
Source: WAEC / JAMB / NECO Classroom Archive (Record #14048)
Physics
UTME / JAMB 2008
Reflection, Refraction & Dispersion of Light
Solution
An object of heights 5 cm is placed at 20 cm from a concave mirror of focal length 10 cm. the image height is?
A
20 cm
B
15 cm
C
10 cm
D
5 cm
medium Difficulty
Verified Correct Answer: Option D
Physical Principles & Numerical Solution
(1)/V + (1)/U = (1)/f
(1)/V + (1)/20 = (1)/10
(1)/V = (1)/10 - (1)/20 = (2 -1)/20 = (1)/20
∴ V = 20 cm
mag = (image height)/object height = (v)/u
(X)/5 = (20)/50
X = 5 cm
Source: WAEC / JAMB / NECO Classroom Archive (Record #14049)
Physics
UTME / JAMB 2008
Reflection, Refraction & Dispersion of Light
Solution
Convex mirror are used as driving mirrors because images formed are?
A
erect, virtual and diminished
B
erect, real and diminished
C
erect, virtual and magnified
D
inverted virtual and diminished
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
Image formed by convex mirror is always erect, virtual and diminished
Source: WAEC / JAMB / NECO Classroom Archive (Record #14052)
Physics
UTME / JAMB 2008
Reflection, Refraction & Dispersion of Light
Solution
An object placed at the bottom of a well full of clear water appears closer to the surface due to?
A
diffraction
B
reflection
C
refraction
D
polarization
medium Difficulty
Verified Correct Answer: Option C
Physical Principles & Numerical Solution
Real depth and apparent dept is due to refraction
Source: WAEC / JAMB / NECO Classroom Archive (Record #14056)
Physics
UTME / JAMB 2008
Reflection, Refraction & Dispersion of Light
Solution
If a concave lens of focal length 12cm is used to produce a real image four times the size of the object, how far from the lens must the object be placed?
A
10 cm
B
15 cm
C
20 cm
D
25 cm
medium Difficulty
Verified Correct Answer: Option B
Physical Principles & Numerical Solution
Magnifications = V/U = 4
∴ V = 4U
1/V + 1/U = 1/f
1/4u + 1/U = 1/12
5/4U = 1/12
4U = 12 x 5 = 60
∴ U = 15 cm
Source: WAEC / JAMB / NECO Classroom Archive (Record #14490)
Physics
UTME / JAMB 2008
Waves, Sound & Vibrations
Solution
The fundamental property of a propagating wave which depends only on the source and not the medium of propagation is the?
A
wavelength
B
harmonics
C
frequency
D
velocity
medium Difficulty
Verified Correct Answer: Option C
Physical Principles & Numerical Solution
Timber/ quality depends on the overtones or harmonics, and timber is a characteristic property of source of sound,
A harmonic is a wave with a frequency that is a positive integer multiple of the fundamental frequency,
These rest on the fundamental property of FREQUENCY.
Source: WAEC / JAMB / NECO Classroom Archive (Record #14046)
Physics
UTME / JAMB 2008
Lenses & Optical Instruments
Solution
In the microscope, the eyepiece lens merely acts as?
A
an inverter
B
a refiner
C
a diminisher
D
a magnifier
medium Difficulty
Verified Correct Answer: Option D
Physical Principles & Numerical Solution
The basic function of microscope is magnification
Source: WAEC / JAMB / NECO Classroom Archive (Record #14057)
Physics
UTME / JAMB 2008
Lenses & Optical Instruments
Solution
Short sightedness can be corrected by what type of lens?
A
Concave lens
B
Convex lens
C
Converging lens
D
Mirrors
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
Shortsightedness is corrected using a concave (curved inwards) lens which is placed in front of a myopic eye
Source: WAEC / JAMB / NECO Classroom Archive (Record #14058)
Physics
UTME / JAMB 2008
Units, Measurements & Dimensional Analysis
Solution
The dimension of electromotive force are?
A
ML2T-3I-1
B
ML2T-3I-2
C
M2LT-2I-1
D
M2L2T-1I-1
medium Difficulty
Verified Correct Answer: Option A
Physical Principles & Numerical Solution
Electrical work W = QE,
Where Q is the quantity of change and E is the electromotive force.
∴ E = W = FxDQ_It
Where D is the displacement,I = current and t = time
But dimension of force,
= unit of mass x unit of Acceleration
= unit of mass xunit of velocityunit of time
= unit of mass x unit of displacement__unit of time x unit of time
ML/T2 = MLT-2
∴ Dimension of emf E
= MLT-2L = ML2T-3I-1__IT
Source: WAEC / JAMB / NECO Classroom Archive (Record #14482)