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Tambaya 1 Rahoto
Which of the following statements is TRUE of photoelectric effect?
Tambaya 2 Rahoto
If an object is placed in front of two mirrors inclined at 90o, how many images will be formed?
Tambaya 3 Rahoto
Which of the following units is equivalent to kgms-1?
Bayanin Amsa
kgms-1 = massdistance
since, F = ma = kgms-1 = N
kgms-1 = Ns
Tambaya 4 Rahoto
Four lenses are being considered for use as a microscope objective. Which of the following focal lengths is most suitable?
Bayanin Amsa
Tambaya 5 Rahoto
Bayanin Amsa
Tambaya 7 Rahoto
A load of 5N gives an extension of 0.56cm in a wire which obeys Hooke's law. What is the extension caused by a load of 20N?
Tambaya 8 Rahoto
The direction of the magnetic field at a point in the vicinity of a bar magnet is
Bayanin Amsa
Tambaya 9 Rahoto
A 50kg block is dropped from a point 10cm above as shown in the fig above. if the force constant of the spring is 4.0 x 104Nm-1, find the maximum compression of the spring [g = 10ms-2]
Bayanin Amsa
Tambaya 10 Rahoto
An object 3.0cm high is placed 60.0cm from a converging lens whose focal length is 20.0cm. Calculate the size of the image formed
Bayanin Amsa
F = UVU+V
20 = 60×V60+V
V = 30cm
similarly, UV = height of objectheight of image
6030 = 3h
h = 1.5cm
Tambaya 11 Rahoto
Two capacitance of 6μ F and 8μ F are connected in series. What additional capacitance must be connected in series with this combination to give a total of 3μ F
Tambaya 13 Rahoto
A man walks 8km north and then 5km in a direction 60o east of north. Find the distance from his starting point
Bayanin Amsa
R = √52+82−2×5×8×cos120o
R = √129
= 11.36km
Tambaya 14 Rahoto
A body rolls down a slope from a height of 100m. its velocity at the foot of the slope is 20ms-1. What percentage of its initial potential energy is converted into kinetic energy? [g = 10ms-1]
Bayanin Amsa
P.E = mgh = 1000m joules
K.E = 12 mv2 = 200m joules
%converted = 200m1000m x 100
= 20%
Tambaya 16 Rahoto
A current of 0.5A flows through a resistor when connected to a 40-V battery. How much energy is dissipated in 2 minutes?
Bayanin Amsa
Electrical energy = IVT
= 0.5 x 40 x 2 x 60
= 2400J
Tambaya 17 Rahoto
When the length I of a piece of wire under constant tension is varied, the relationship of the frequency of the vibration fα / is
Bayanin Amsa
F = 12L√Tm
Tambaya 18 Rahoto
A ray of light is incident at an angle of 30o on one top surface of a parallel-sided glass block of refractive index 1.5. The ray finally emerges from the lower surface. What is the angular deviation of the emergent ray?
Tambaya 19 Rahoto
The distance between the fixed points of a centigrade thermometer is 20cm. What is the temperature when the mercury level is 4.5cm above the lower mark?
Bayanin Amsa
20cm .... 100oC
4.5cm .... θ
0cm ....0oC
4.5−020−0 = 0−0100−0
θ = 22.5oC
Tambaya 20 Rahoto
What type of reaction is represented by the following scheme? 21X + 21Y + 32Z + 10n + energy
Bayanin Amsa
Tambaya 21 Rahoto
As a result of air at the top of a barometer, the height of the mercury column is 73.5cm when it should be 75.0cm; the volume of the space above the mercury is 8.0cm3. Calculate the correct barometer height when the barometer reads 74.0cm and the volume of the space above the mercury is 6.0cm3.
Bayanin Amsa
Using, P1P1 = P2P2
(75 - 73.5) x 8 = (X - 74) x 6
X = 76cm
Tambaya 22 Rahoto
The velocity time graph above describes the motion of a particle between two points P and Q. What is the distance between P and Q?
Bayanin Amsa
Tambaya 23 Rahoto
Which of the following phenomena explains the fact that a house whose roof is coated with white paint will be cooler in the hot season than one coated with black paint ?
Tambaya 24 Rahoto
A cube of side 10cm and mass 0.5kg floats in a liquid with only 15 of its height above the liquid surface. What is the relative density of the liquid?
Bayanin Amsa
Height below liquid = 1 - 15 = 45
volume of cube = 103cm3
volume of liquid displaced = 45 x 1000
= 800cm3
density of liquid displaced;
= 500800
= 0.625cm-1
Tambaya 25 Rahoto
he coefficient of static friction between a 40kg crate and concrete surface is 0.25. Find the magnitude of the minimum force needed to keep the crate stationary on the concrete base inclined at 45o to the horizontal. [G = 10ms-1]
Bayanin Amsa
momentum force = R5nθ - μ Rcosθ
Fm = (40 x 10 x sin 45) - (40 x 10 x 0.25 x cos 45)
= 212N
Tambaya 26 Rahoto
22,000J of heat is required to raise the temperature of 1.5kg of paraffin from 20oC to 30oC. Calculate the specific heat capacity of paraffin.
Tambaya 27 Rahoto
The length of a side of a metallic cube at 20oC is 5.0cm. Given that the linear expansivity of the metal is 4.0 x 10-5k-1, find the volume of the cube at 120oC .
Bayanin Amsa
Y = V2−V1V1×θ
3 x 4 x 10-5 = V2−125125×(120−20)
V2 = 126.50cm3
Tambaya 28 Rahoto
A pool of water appears to be 1.0m deep when viewed vertically from above. If the refractive index of water is 1.33, what is the actual depth of the pool?
Bayanin Amsa
n = real depthapparent depth
1.33 = real depth1
real depth = 1.33cm
Tambaya 30 Rahoto
A radioactive sample initially contains N atoms. After three half-lives the number of atoms that have disintegrated is
Tambaya 31 Rahoto
A jet engine develops a thrust of 270Ns when the velocity of the exhaust gases relative to the engine is 300ms-1. What is the mass of the material ejected per second?
Bayanin Amsa
Thrust = force x time
thrust = m(v−u)t x t1
270 = m(300 - 0)
m = 0.90kg
Tambaya 33 Rahoto
he lowest note emitted by a stretched string has a frequency of 40Hz. How many overtones are there between 40Hz and 150Hz?
Bayanin Amsa
In stretched strings the overtones are in odd multiple of Fo.
F1 = 3Fo
= 3 x 40 = 120Hz
F2 = 5Fo
= 5 x 40
= 200Hz
Tambaya 34 Rahoto
When two parallel wires carry currents in opposite directions, the force on either wire is
Bayanin Amsa
Tambaya 36 Rahoto
A constant force of 40N acting on a body initially at rest gives an acceleration of 0.1ms-2 for 4s. Calculate the work done by the force
Bayanin Amsa
X = ut + 12 at2
= (0 x 4) + (12 x 0.1 x 4 x 4)
= 0.8m
workdone = force x distance
= 40 x 0.8
= 32J
Tambaya 37 Rahoto
Isotopes are nuclei which have
Tambaya 38 Rahoto
If a beaker is filled with water it is observed that the surface of the water is not horizontal at the glass-water interface. This behavior is due to
Bayanin Amsa
Tambaya 39 Rahoto
Hot water is added to three times its mass of water at 10oC and the resultant temperature is 20oC. What is the initial temperature of the hot water?
Bayanin Amsa
Heat loss = heat gained
mh x ch x θ h = mc x cc x θ c
mh x ch x (θ - 20) = mc x cc x (20 - 10)
ch = cc ; mc = 3mh
therefore, θ = 50oC
Tambaya 40 Rahoto
In the figure above, M and N are insulated metal spheres in contact. A negatively charged ebonite rod P is I brought near M. When M and N are Separated and the rod is taken away, which of the following statements is correct
Bayanin Amsa
Tambaya 41 Rahoto
The fig above shows two connected bodies of masses M1 and M2 in equilibrium under gravity. The tension in the upper string is
Bayanin Amsa
Tambaya 42 Rahoto
Which of the following statements supports the assumption that light travels in straight lines?
Bayanin Amsa
Tambaya 43 Rahoto
An elevator of mass 4800kg is supported by a cable which can safely withstand a maximum tension of 60 000N. The maximum upward acceleration the elevator can have is
Bayanin Amsa
a = Fm
= 60000−(4800×10)4800
= 2.5ms-2
Tambaya 44 Rahoto
A wave has a frequency of 2Hz and a wavelength of 30cm. The velocity of the wave is
Bayanin Amsa
V = Fλ
= 2 x 0.3
= 0.6ms-1
Tambaya 45 Rahoto
Calculate the amount of heat required to convert 2kg of ice at 2oC to water at 0oC. [specific heat capacity of ice = 2090Jkg-1oC-1, specific latent heat of fusion of ice = 333kJkg-1]
Bayanin Amsa
Q = mL + mcθ
= (2 x 333000) + (2 x 2090 x 2)
= 674 360J
Tambaya 46 Rahoto
In which of the following are the substance arranged in descending order of their thermal conductivities?
Bayanin Amsa
Tambaya 47 Rahoto
A galvanometer of resistance 20Ω
is to be provided with a shunt that 110
of the whole current in a circuit passes through the galvanometer. The resistance of the shunt is
Tambaya 48 Rahoto
The fig above represents the main sequence of energy conversion at Kainji dam. What is the efficiency of the system?
Bayanin Amsa
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