JAMB UTME - Physics - 1999
Swali 1 Ripoti
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Swali 2 Ripoti
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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Swali 3 Ripoti
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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
Swali 4 Ripoti
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
Swali 5 Ripoti
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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Swali 6 Ripoti
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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Swali 7 Ripoti
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= 80−200.02
= 600.02
= 3000Km-1
= 3.0 x 103Km-1
Swali 8 Ripoti
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Swali 9 Ripoti
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Swali 10 Ripoti
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Swali 11 Ripoti
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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
Swali 12 Ripoti
In the circuit above, The potential across each capacitor is 100V. The total energy stored in the two capacitors is
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Swali 13 Ripoti
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Swali 14 Ripoti
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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Swali 15 Ripoti
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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Swali 16 Ripoti
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Let P1 = P0 and V1 = V0, then solve accordingly.
Swali 17 Ripoti
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Swali 18 Ripoti
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Swali 19 Ripoti
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Swali 20 Ripoti
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Swali 21 Ripoti
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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
Swali 22 Ripoti
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Swali 23 Ripoti
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
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Swali 24 Ripoti
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Swali 25 Ripoti
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800(25−0)20×25 = 2.5 x 10 4 watts
Swali 26 Ripoti
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Swali 27 Ripoti
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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
Swali 28 Ripoti
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Swali 29 Ripoti
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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Swali 30 Ripoti
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
Swali 31 Ripoti
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
Swali 32 Ripoti
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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
Swali 33 Ripoti
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Swali 34 Ripoti
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Swali 35 Ripoti
The diagram above shows a lift pump with valves at P and Q. During a downward stroke of the piston
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Swali 36 Ripoti
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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
Swali 37 Ripoti
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Swali 38 Ripoti
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Swali 39 Ripoti
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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Swali 40 Ripoti
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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
Swali 41 Ripoti
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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Swali 42 Ripoti
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Swali 43 Ripoti
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Swali 44 Ripoti
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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Swali 45 Ripoti
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
Swali 46 Ripoti
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Swali 48 Ripoti
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Swali 49 Ripoti
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
Swali 50 Ripoti
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.
