JAMB UTME - Physics - 2018
Question 1 Report
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Vernier calipers have both a fixed main scale and a moving vernier scale. The main scale is graduated in either millimetres or tenths of an inch. The vernier scale allows much more precise readings to be taken (usually to the nearest 0.02mm or 0.001 inch) in comparison to a standard ruler (which only measures to th nearest 1mm or 0.25 inch).
The vernier scale was invented by French mathematician Pierre Vernier in 1631. As part of the vernier caliper, it is used together with the main scale, and helps to provide very precise measurements. Vernier calipers usually show either imperial or metric measurements, but some measure in both.
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Question 3 Report
A solid cube of side 50cm and mass 75kg floats in a liquid with \( \frac{1}{3} \) of its height above the liquid surface. The relative density of the liquid is?
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= 23 (0.5)3
Mass of liquid displaced = mass of floating cube = 75kg
Density of liquid = massvolume
= 75(73(0.5)) × 3
= 0.9 × 103kgm−3
R.D of liquid = (0.9)(1.0) × 103
= 0.9
Question 4 Report
Which of the following may be used to explain a mirage?
I. Layers of air near the road surface have varying refractive indices in hot weather
II. Road surfaces sometimes become good reflectors in hot weather
III. Light from the sky can be reflected upwards after coming close to the road surface.
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Question 5 Report
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Question 6 Report
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Weight of water displaced = upthrust = 30 - 21 = 9N
Mass of water displaced = 910
= 0.9kg
Volume of object = 9 × 10−4
m3
= (9 × 10−4
) (1.4 ×103)
= 1.26kg = 12N
30 - 12.6 = 17.4N
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Question 8 Report
A ball of mass 5.0kg hits a smooth vertical wall normally with a speed of \(2\text{ms}^{-1}\). Determine the magnitude of the resulting impulse
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Question 9 Report
Which of the following statements are TRUE of isotopes?
I. Isotopes of an element have the same chemical properties because they have the same number of electrons
II. Isotopes of elements are normally separated using physical properties
III. Isotopes of an element have the same number of protons in their nuclei
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Question 11 Report
In the diagram given the hanging mass m2 is adjusted until m1 is on the verge of sliding. The coefficient of static
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Question 12 Report
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According to Sudipa Sarkar, the formation of shadows with sharp edges demonstrates the rectilinear propagation of light, i.e. The fact that light travels in straight line. When an opaque obstacle is placed between a source of light and a screen, a shadow of the obstacle is formed on the screen. The kind of shadow depends on the size of the source of light. If it is a point source (light from a small hole), the shadow obtained is a region of total darkness, called umbra.
If an extended source of light, e.g. a bulb, is used, the umbra is surrounded by a region of partial darkness, called penumbra. The moon is seen because it reflects the sun's light. An eclipse of the moon (lunar eclipse) occurs when the earth comes between the sun and the moon and prevents some of the light from the sun from reaching the moon. In other words, the earth casts its shadow on the moon. The solar eclipse occurs when the moon comes between the sun and the earth.
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Question 19 Report
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But in the case of bigger drops of mercury, the potential energy due to gravity is predominant over the potential energy due to surface tension.Consequently, to keep equilibrium , the mercury drop tends to assume minimum potential energy as possible, the drop becomes oval in shape and lower center of gravity.
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Question 23 Report
An electric heating coil rated at 1KW is used to heat 2kg of water for 2 minutes. The initial water temperature is 30\(^{o}\)C. Taking the specific heat of the water as 4,000Jkg\(^{-1}\) and neglecting that of the container, the final water temperature is
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Question 25 Report
A 20kg mass is to be pulled up a slope inclined at 300 to the horizontal. If efficiency of the plane is 75%. The force required to pull the load up the plane is J [g=10ms\(^{-2}\)]
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Question 26 Report
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Question 27 Report
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Question 28 Report
An object moves in a circular path of radius 0.5m with a speed of \(1ms^{-1}\). What is its angular velocity?
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Question 29 Report
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Question 30 Report
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= E3E2
Question 31 Report
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V = 100cm
U = ?
1U + 1V = 1F
120 + 1100 = 1F
5+1100 = 1F
F = 1006
= 16.7cm
= 17cm
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Question 33 Report
In the diagram shown, If the south-poles of two magnets stroke a steel bar, the polarities at T and V will respectively be
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Question 34 Report
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Change in Momentum = Mass x (change in velocity)
Change in Momentum = Mass x (v - u)
Mass = 100g = 0.1kg
U = 2ms−1
V = 10ms−1
Change in momentum = m (v − u)
= 0.1 (10 − 2)
= 0.1 (8)
= 0.8Ns
Question 35 Report
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Question 37 Report
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The speed of sound in air is approximately 343 meters per second at room temperature. The formula for the speed of sound is:
Speed of sound = Frequency × Wavelength
In this problem, we are given the frequency (260 Hz) and the wavelength (1.29 m) of the sound wave. We can use these values to calculate the speed of sound:
Speed of sound = 260 Hz × 1.29 m = 335.4 m/s
Next, we need to use the fact that the man hears his echo 2 seconds after he shouted. Since the sound wave traveled from the man to the hill and then back to the man, the total distance traveled by the sound wave is twice the distance from the man to the hill. We can use the formula:
Distance = Speed × Time
to calculate the distance from the man to the hill:
Distance = (335.4 m/s) × (2 s/2) = 335.4 m
Therefore, the hill is 335.4 meters away from the man. The answer is option (B), 335.4m.
Question 38 Report
If the fraction of the atoms of a radioactive material left after 120years is \( \frac{1}{64} \), what is the half-life of the material? \( \frac{1}{64} \)
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Question 39 Report
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Shell?s law:. 7 = Sin20Sinr0
Vg = Sin300Sinr0
Sinr0 = 3Sin3004
Sin r0 = 0.375
R o = Sin-1 (0.375)
R o = 22.02 o
R o = 22 o
Question 40 Report
What is the resultant resistance of the circuit in the image shown?
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= 1/R = 1/R1 +1/R2
1/R = 1/2 +1/2 = 1
Resistance are now in series
R = 1 + 3 + 4
= 8 ohms
