JAMB UTME - Physics - 1999
Pregunta 1 Informe
The figure above represents a frictionless pulley system in which a weight W is in equilibrium with a weight of 40N. Find the value of W.
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Pregunta 3 Informe
A 3000W electric cooker is to be used on a 200V mains circuit. Which of the fuses below can be used safely with the cooker?
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The maximum current drawn by the cooker is given by;
I = P/V
∴ I = 3000/200
I = 15A
Thus the most suitable fuse to be used is a 10A fuse
Pregunta 4 Informe
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Pregunta 5 Informe
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Pregunta 6 Informe
The diagram above shows a solid figure with base PQ and center of gravity G on a inclined plane. Which of the following statements is correct
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Pregunta 7 Informe
Calculate the mass of ice that would melt when 2kg of copper is quickly transferred from boiling water to a block of ice without heat loss;
Specific heat capacity of copper = 400JKg-1K-1
Latent heat of fusion of ice = 3.3 x 105JKg-1
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Pregunta 8 Informe
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E = hf = hV/λ (since V = fxλ)
But in terms of mass M, E = ∆MV2
∴ ∆MV2 = hV/λ
∆MV = h/λ
∴ V = h/λ∆M
V = 6.63 x 10-34/(10-27 x 10-8)
V = 6.63 x 10-34/10-35
V = 6.63 x 10-34+35
V = 6.63 x 10
V = 66.3ms-1
Pregunta 9 Informe
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Strain = e/l0. = (10.05 - 10.00)/10.00 = 0.005
Thus Y = 107/0.005 = 2 . 0 x 109Nm-2
Pregunta 10 Informe
The diagram above shows the velocity-time graph of a vehicle. Its acceleration and retardation respectively are
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∴ acceleration and retardation = 4m/s2; 2m/s2
Pregunta 11 Informe
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Pregunta 12 Informe
In the circuit above, The potential across each capacitor is 100V. The total energy stored in the two capacitors is
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Pregunta 13 Informe
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However, the effective internal resistance adds as parallel arrangement given as
1/r = 1/r1 + 1/r2 + 1/r3 + 1/r4
= 1/4 + 1/4 + 1/4 + 1/4
= 1Ω
∴ r = 1Ω
Answer = 1.5V, 1Ω
Pregunta 14 Informe
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Pregunta 15 Informe
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Pregunta 16 Informe
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R = igrg/(I - ig)
Where R = 0.05Ω
rg = 5Ω
I = 2M
∴ ig = IR/(rg + R)
= (2 x 0.05)/(5 + 0.05)
= 0.10/5.05
= 0.0198A
= 19.8mA
= 20mA
Pregunta 17 Informe
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Pregunta 18 Informe
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Pregunta 19 Informe
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Energy before hitting ground is = P.E at the height of 15m.
P.E = mgh = 0.1 x 10 x 15 = 15 J
Pregunta 20 Informe
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Pregunta 21 Informe
The diagram above shows a lift pump with valves at P and Q. During a downward stroke of the piston
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Pregunta 22 Informe
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This energy is converted to heat energy - mcΔt
∴ From the principle of energy conversion,
mcΔt = mgh
m x 450 x Δt = m x 10 x 20
∴ Δt = m x 10 x 20/(m x 450)
= 200/450
= 4/9°C
Pregunta 23 Informe
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Pregunta 24 Informe
In the circuit above, the ammeter reads a current of 5.0 A when R = 8? and reads 7.0A when R = 5?. The value of the unknown resistance X is
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Pregunta 25 Informe
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Pregunta 26 Informe
I. A liquid boils when its saturated vapour pressure is equal to the external pressure
II. Dissolved substances in pure water lead to increase in the boiling point.
III. When the external pressure is increased, the boiling point increases.
IV. Dissolved substances in pure water decrease the boiling point.Which combination of the above are peculiarities of the boiling point of a liquid?
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Pregunta 27 Informe
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Pregunta 28 Informe
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Let P1 = P0 and V1 = V0, then solve accordingly.
Pregunta 29 Informe
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= 80−200.02
= 600.02
= 3000Km-1
= 3.0 x 103Km-1
Pregunta 30 Informe
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Pregunta 31 Informe
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Pregunta 32 Informe
In the J-tube above, Y and X are on the same horizontal level and 30cm3 of air is trapped above Y when the atmospheric pressure is 75cm Hg, calculate the volume of air trapped above Y when 15cm Hg is now poured into the limb above X
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Pregunta 33 Informe
The equation of a wave travelling along the positive x-direction is given by;
Y = 0.25 x 10-3 sin (500t - 0.025x).
Determine the angular frequency of the wave motion.
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Pregunta 34 Informe
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800(25−0)20×25 = 2.5 x 10 4 watts
Pregunta 35 Informe
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Pregunta 36 Informe
2311Na + Proton → pqX + alpha particle
What are the values of p and q respectively in the equation above?
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Represent;
2311Na + 11P → pqX + 42He
Thus from the above equations, p = 20 and q = 10
Pregunta 37 Informe
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Pregunta 38 Informe
The diagram above represents a transverse electromagnetic wave travelling with speed 3.0 x 108ms-1. What is the frequency of the wave.
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Where λ = wavelength
From the above, the distance OA = one wavelength; AB = one wave length and BC = one wavelength.
=> OC = 3 wavelength = 3λ
∴3λ = 0.3M
λ = 0.3/3
= 0.1m
∴ f = V/λ = (3.0 x 108) / 0.1
= 3.0 x 109Hz
Pregunta 39 Informe
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(0.05 x 200) - (0.95 x 0) = (0.05 + 0.95) x V (since collision is inelastic).
Thus V = 10m/s.
K.E = 1/2 (0.05 + 0.95) x 102
K.E = 1/2 (1 x 100) = 50 J
Pregunta 40 Informe
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Pregunta 41 Informe
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Pregunta 42 Informe
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Pregunta 43 Informe
The diagram above shows a magnet X with its south pole moved along a soft - iron bar PQ in the direction shown. After some time, the poles at P and Q respectively are
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Pregunta 44 Informe
In the diagram above, if the internal resistance of the cell is zero, the ration of the powers P1 and P2 dissipated by R1 and R2
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Pregunta 45 Informe
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Pregunta 46 Informe
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Pregunta 47 Informe
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Pregunta 48 Informe
In fleming's right-hand rule, the thumb, the forefinger and the middle finger if held mutually at right angles represent respectively, the
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Pregunta 49 Informe
A solid weigh 10 .00 N in air, 6 N when fully immersed in water and 7 . 0 N when fully immersed in a liquid X. Calculate the relative density of the liquid, X.
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R.D = loss in weight in liquid X loss in weight in water.
R.D = (10 - 7)/(10 - 6) = 3/4
Pregunta 50 Informe
In the series a.c circuit shown above, the p.d across the inductor is 8Vr.m.s and that across the resistor is 6Vr.m.s. The effective voltage is
