A tuber of cassava can be processed into powder. This explains the face that
отговор
(D)
matter is made up of tiny particle
2
A piece of metal of relative density 5.0 weighs 60N in air. Calculate its weight when fully immersed in water
отговор
(C)
48N
3
The tendency of a body to remain at rest when a force is supplied to it is called
отговор
(C)
inertia
4
A force acts on a body for 0.5s changing its momentum from 16.0kg ms-1 to 21.0kgms-1, calculate the magnitude of the force
отговор
(D)
10.0N
5
A moving object is said to have a uniform acceleration if its
отговор
(C)
velocity increases by equal amount in equal time intervals
6
The period of an oscillatory motion is defined as the
отговор
(C)
time to complete one oscillation
7
The mass on a loaded spiral spring oscillates vertically between two extreme positions P and R equidistant from the equilibrium position Q. Which of the following statements about the system is not correct
отговор
(D)
the total energy of the system is always constant
8
A ball f mass 5.0kg hits a smooth vertical wall normally with a speed of 2ms-1. Determine the magnitude of the resulting impulse
отговор
(B)
10.0kgms-1
9
Which of the following statements correctly defines a simple machine? a device
отговор
(C)
with which work can be done easily
10
A platinum resistance thermometer has a resistance 4\(\Omega\) at 0oC and 10\(\Omega\) at 100oC. Assuming the resistance changes uniformly with temperature. Calculate the resistance of the thermometer when the temperature is 45oC.
отговор
(B)
6.7\(\Omega\)
11
A metal rod of length 100cm is heated through 100ºC, calculate the change in length of the rod [linear expansivity of the material of the rod is 3 x 10\(^{-5}\)K\(^{-1}\)]
отговор
(B)
3mm
12
The heat capacity of a calorimeter is the amount of energy required to
отговор
(C)
change the temperature of the calorimeter
13
Which of the following statement about latent heat of vaporization is correct? It
отговор
(B)
breaks completely the force of attraction completely between the molecules of a liquid
14
When the pressure of a fixed mass of gas is doubled at constant temperature, the volume of the gas is
отговор
(D)
halved
15
The volume of a given mass of an ideal gas at 327k and 9.52 x 104 Pa is 40cm3. calculate the volume of the gas at 273k and 1.034 x 105Pa.
отговор
(D)
30.75cm3
16
A wave of weight length 0.30m travels 900m in 3.0s, calculate its frequency
отговор
(C)
1000Hz
17
Which of the following condition is necessary for the occurrence of total internal reflection of light?
отговор
(C)
the angle of incidence must be greater than the critical angle
18
The image which cannot be formed on a screen is said to be
отговор
(D)
virtual
19
An object is placed on the principal axis and at the centre of curvature of a concave mirror, the image of the image formed by the mirror is
отговор
(B)
real and inverted
20
A converging lens produces an image four times as large as an object placed 25cm from the lens. Calculate its focal length
отговор
(D)
20cm
21
The horizontal floor of a water reservoir appears to be 1.0m deep when viewed vertically from above. If the refractive index of water is 1.35, calculate the real depth of the reservoir
отговор
(B)
1.35m
22
A converging lens has a focal length of 5cm. Determine its power
отговор
(A)
+20.0
23
Which of the following pairs of rays shows the widest separation in the spectrum of white light?
отговор
(B)
orange and indigo
24
Which of the following statements about the human eye and the camera is correct?
отговор
(C)
the inside of both of them is blackened to absorb unwanted light
25
The speed of sound in air is is directly proportional to
отговор
(D)
the square roor of its temperature on the absolute scale
26
A sonometer wire of linear density 0.08kg m-1 subjected to a tension of 800N is plucked. Calculate the speed of a pulse which moves from one end of the wire to the other
отговор
(B)
100.0ms-1
27
Which of the following instruments gives a pure note when sounded?
отговор
(C)
tunning fork
28
Which of the following features of an electrostatic line of force is not correct?
отговор
(D)
it can cross another line of force in a region of intense electric field
29
Which of the following statement about force is correct ?
отговор
(C)
fields are real but their corresponding field lines are imaginary
30
A positively charged glass rod is placed by near the cap of a positively charge electroscope. The divergence of the leaf is observed to
отговор
(B)
increase
31
Two identical cells each of e.m.f 2v and internal resistance 1.0\(\Omega\) are connected in parallel. The combination is connected to an external load of 1.5\(\Omega\). Calculate the current in the circuit
отговор
(B)
1.00A
32
Which of the following factors does not affect the the electric resistance of a wire?
отговор
(B)
mass
33
A current of 10A passes through a conductor for 10s, calculate the charge flowing through the conductor
отговор
(A)
100.0C
34
A lamp is rated 240V 60W, calculate the resistance of its filament
отговор
(C)
960\(\Omega\)
35
The maximum power dissipated by a 100\(\Omega\) resistor in a circuit is 4W. Calculate the voltage across the resistor
отговор
(B)
20V
36
One difference between a reactance and a resistance in an alternating current circuit is
отговор
(D)
the current in a reactance is lower than in the resistance
37
The direction of induced current in a straight wire placed in magnetic field is determined by using?
отговор
(D)
Lenz's law
38
Which of the following statements about an electromagnet is not correct?
отговор
(D)
it has permanent poles
39
Which of the following statements is not true of the isotopes of an element? They
отговор
(D)
have the same mass number
40
Which of the following statements is true of ultra violet radiations? It
отговор
(C)
is an electromagnetic wave
41
A radioactive element has a decay constant of 0.077s-1, calculate its half life
отговор
(B)
9.0s
42
The minimum energy required to remove an electron from an atom is known as
отговор
(B)
ionization energy
43
Nuclear fission is preferred to nuclear fusion in the generation of energy because?
отговор
(A)
very high temperature are required for fusion
44
Which of the following reactions represents nuclear fusion?
отговор
(A)
\(^2_1H + ^2_1H \to ^3_2He + ^1_0n\)
45
The diagram above shows the resultant electric field pattern due to two electric point charges P and S. Which of the following statements is correct?
