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Frage 1 Bericht
A lens of focal length 12.0cm forms an upright image three times the size of a real object. The distance between the object and the images is
Antwortdetails
F = 12cm, V = 3u
F = uvu+v
12 = u×3uu+3v
u = 16cm, and v = 48cm
therefore, distance between u and v
v = 48 - 16 = 32cm
Frage 2 Bericht
A pencil is placed vertically between a concave mirror and its focal point. The image of the pencil in the mirror will be
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Frage 3 Bericht
A constant force of magnitude F acts on an object of mass 0.04kg initially at rest at a point O. if the speed of the object when it has moved 50m from O is 500ms-1, what is the value of F?
Antwortdetails
F = ma and V2 = U2 + 2aX
F = m(V2−U2)2X
= 0.04(5002−02)2×50
F = 100N
Frage 4 Bericht
What is the effect of the increase in the size of the hole of a pin-hole camera on the image? it
Frage 5 Bericht
Which of the following properties makes metals ideal for cooking utensils?
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Frage 6 Bericht
If the refractive index of glass is 1.5, what is the critical angle at the air-glass interface?
Antwortdetails
sin ic 1n = 11?5
i = sin-111?5
= sin-11015
= sin-123
Frage 7 Bericht
A dentist obtains a linear magnification of 4 of a hole in a tooth by placing a concave mirror at a distance, of 2.0cm from the tooth. The radius of Curvature of the mirror is
Antwortdetails
v = 4u, if u = 2cm, v = 8cm
F = uvu+v
= 2×82+8
= 1.6cm
r = 2F
= 2 x 1.6
= 3.2cm
Frage 9 Bericht
Which of the following is a derived unit?
Antwortdetails
Force is a derived quantity, it's unit is a derived unit
Frage 12 Bericht
A ball is thrown vertically into the air with an initial velocity u. What is the greatest height reached?
Antwortdetails
Using V2 = U2 - 2gS
V = 0ms-1 at greatest height
S = u22g
Frage 13 Bericht
The angle between the magnetic meridian and the geographic meridian at a locality on the earth is the
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Frage 14 Bericht
When two objects P and Q are supplied with the same quantity of heat, the temperature change in P is observed to be twice that of Q. The ratio of the specific heat capacity of P to Q is
Antwortdetails
θ p = 2θ q
mq = 2mp
Cp X mp X θ p = Cq x mq x θ q
CpmqθqCqmpθq = θq×2mp2θqmp
CpCq = 22
Frage 17 Bericht
In an experiment in which molten naphthalene is allowed to cool, the cooling curve in fig 5 was obtained, the temperature 80∘C
is known as
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Frage 18 Bericht
The mode of heat transfer which does not require a material medium is
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Frage 19 Bericht
A rectangular tank contains water to a depth of 2m, if the base is 4m x 3m, calculate the force on the base (Density of water = 103kgm-3, g = 10ms-2)
Antwortdetails
Volume = 2 x 4 x 3 = 24m3
mass = V x D = 24 x 103
F = mg
= 24 x 103 x 10
= 24 x 104
Frage 20 Bericht
Which of the following is most strongly deflected by magnetic field?
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Frage 21 Bericht
A gas occupies a volume of 300cm3at a temperature of 27oC. What is its volume at 54oC, when the pressure is constant?
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V1T1 = V2T2
30027+273 = V254+273
V2 = 327cm3
Frage 22 Bericht
In which of the following arrangements is the wavelength in an increasing order?
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Frage 23 Bericht
Fig 1 is a graph of force against extension for a spiral spring, the force constant of the spring is given by the
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Frage 25 Bericht
The sign of the change on a charged glass rod may be determined with
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Frage 26 Bericht
When a box of mass 45kg, is given an initial speed of 5ms-1 it slides along a horizontal floor a distance of 3m before coming to a rest. what is the coefficient of kinetic friction between the box and the floor? (G = 10ms-2)
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Frage 27 Bericht
A wave of frequency 10Hz forms a stationary wave pattern in a medium where the velocity is 20cms-1. The distance between adjacent nodes is
Antwortdetails
λ = vf
= 2010
= 2cm ; distance between adjacent nodes
Frage 28 Bericht
A uniform meter rule QR is balanced on a knife edge which is 55cm from R, when a mass of 10g is hung at P as shown above, the mass of the meter rule is (Note that QP is 10cm)
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Frage 30 Bericht
Which of the following assumptions is made in a simple pendulum experiment? the
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Frage 32 Bericht
A man clapping his hands at regular intervals observes that the echo of a clap coincides with the next clap. If the reflecting cliff is 160m away and the speed of sound is 320ms-1, what is the frequency of the clapping?
Antwortdetails
Total distance = 2 x 160 = 320cm
Total time = 320320 = 1s
F = 11 = 11
= 1Hz
Frage 33 Bericht
A heavy object is suspended from a string and lowered into water so that it is completely submerged. The object appears lighter because
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Frage 34 Bericht
The wavelength of ultraviolet radiation is 400nm. If the speed of light in air is 3 x 108ms-1, then the frequency of the ultraviolet radiation is
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F = Vλ
= 3×108400×109
= 75 x 1015Hz
Frage 35 Bericht
In fig 6, a ray of light in air strikes a glass plate at an angle of incidence 60 degrees, the reflected ray is observed to be perpendicular to the refracted ray, what is the refractive index of the glass
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Frage 36 Bericht
If the fig above E is an accumulator with negligible internal resistance. and the EMF 9.0V, The the total current is
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Frage 37 Bericht
Two objects, one having three times the mass of the other, are dropped at the same time from a tall building. When they are above the ground, the two objects will have the same
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Frage 39 Bericht
In fig 3, three forces F1, F2, and F3 acting at O are in equilibrium. If the magnitude of F1 is 10N,and the magnitude of F2 is 5N, find the magnitude of F3
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Frage 40 Bericht
Which of the following represents the correct precision if the length of a piece of wire is measured with a meter rule?
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Frage 42 Bericht
Fig 4 represents a block-and-tackle pulley system on which an effort of W newtons supports a load of 120.0N if the efficiency of the system is 40% then the value of W is
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Frage 43 Bericht
The specific latent heat of fusion of lead is the amount of heat required to
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Frage 45 Bericht
A 1000kg elevator is descending vertically with an acceleration of 1.0ms-2, if the acceleration due to gravity is 10ms-2, the tension in the suspending cable is
Antwortdetails
The elevator is descending so the weight acts in line with the acceleration which is downwards. So according to Newton's law,
mg(weight) -R (tension/reaction) = ma
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