In which of the following states of matter do the molecules vibrate about their mean positions?
Trả lời
(B)
solids only
2
Which of the following properties of a steel bar can be measured in terms of the dimension of length only?
Trả lời
(D)
volume
3
In a hydraulic press, a force of 40N is applied to the smaller priston of area 10cm2. If the area of the larger piston is 200cm2, calculate the force obtained
Trả lời
(A)
800N
4
A body of volume 0.046m3 is immersed in a liquid of density 980kgm-3 with \(\frac{3}{4}\) of its volume submerged. Calculate the upthrust on the body. [g = 10ms-2]
Trả lời
(D)
338.10N
5
Which of the following types of types of motion will be produced when a pair of equal and opposite non-collinear parallel forces acts on a body?
Trả lời
(D)
rotational motion
6
A body moving in a circle at constant speed has i. a velocity tangent to the circle ii. a constant kinetic energy iii. an acceleration directed towards the circumference of the circle. Which of the statements above are correct?
Trả lời
(A)
i and ii only
7
A moving body accelerates when it?
Trả lời
(A)
changes its direction at constant speed
8
The following properties of a solid are measured on earth i. weight ii. specific heat capacity iii. density. Which of the properties will hav a different value if measured in space?
Trả lời
(A)
i only
9
Two forces 6N and 8N, act eastwards and northwards respectively on a body. Calculate the magnitude of their equilibrant
Trả lời
(C)
10N
10
The period of a simple pendulum of length 80.0cm was found to have doubled when the length of the pendulum was increased by X. Calculate X.
Trả lời
(D)
240.0cm
11
A body of mass 5kg movimg with a velocity of 30ms-1 due east is suddenly hit by another body and changes its velocity to 50ms-1 in the same direction. Calculate the magnitude of the impulse received.
Trả lời
(A)
100Ns
12
Electric energy is measured in
Trả lời
(C)
kilowatt-hour
13
A stone of mass 0.5kg is dropped from a height of 12m. Calculate its maximum kinetic energy. [g = 10ms-1]
Trả lời
(D)
60.0J
14
A machine of efficiency 80% is used to lift a box. If the effort applied by the machine is twice the weight of the box. Calculate the velocity ratio of the machine
Trả lời
(B)
0.63
15
A faulty thermometer registers 102.5oC t 100oC. If the thermometer has no zero hour, what will it register at 55oC?
Trả lời
(D)
56.4oC
16
A rod of initial lenght 2m at a temperature of 25oC is heated to 80oC. Calculate the increase in length of the rod if its linear expansivity is 4.0 x 10-3K-1
Trả lời
(B)
0.44m
17
as a bicycle Tyre was being pumped up, it was noticed that contrary to Boyle's law the volume increased as the pressure increased. The best explanation of this is that Boyle's law is only true for
Trả lời
(A)
ideal gases
18
It takes 4 minutes to boil a quantity of water using an electrical heating coil. How long will it take to boil the same quantity of water using the same coil if the current is doubled? [Neglect any external heat losses]
Trả lời
(C)
2 minutes
19
When table salt is added to ice, the melting point of the ice
Trả lời
(B)
is lowered
20
Which of the following is used to measure relative humidity?
Trả lời
(D)
hygrometer
21
Which of the following factors affect the rate of evaporation of a liquid? i. Exposed surface area ii Temperature of the surroundings iii. Thermal capacity of the liquid iv. Relative humidity of the surroundings
Trả lời
(D)
i, ii amd iv only
22
The maximum displacement of a vibrating tunning fork is its
Trả lời
(A)
amplitude
23
A boat is rocked by waves of speed 30ms-1 whose successive crest are 10m apart. Calculate the rate at which the boat recieves the waves
Trả lời
(C)
3s-1
24
Which of the following waves is not transverse
Trả lời
(B)
sound waves
25
Light travelling through a small pinhole usually does not make a shadow with a distinct sharp edge because of
Trả lời
(A)
diffraction
26
The angle of incidence of a ray of light on a plane mirror is 55o. Determine the angle between the reflected ray and the mirror
Trả lời
(A)
35o
27
A concave mirror forms a magnified and errect image only when the object is placed
Trả lời
(C)
between the focus and the pole of the mirror
28
A thin lens is placed 50cm from an illustrated object. The image produced has linear magnification of \(\frac{1}{4}\). Calculate the power of the lens in dioptres
Trả lời
(C)
10.0D
29
Which of the following characteristics of light determines its colour?
Trả lời
(B)
wavelength
30
Which of the following is not a part of the electro-magnetic spectrum?
Trả lời
(D)
alpha rays
31
Sound interference is necessary to produce the phenomenon of
Trả lời
(A)
beats
32
A satellite in circular motion around the earth does not have
Trả lời
(B)
a uniform velocity
33
When a conductor mounted on an insulating stand is charged and left for sometime, the conductor eventually loses all its charges. This is because the
Trả lời
(C)
charges on the conductor are neutralized by opposite charges from the surrounding air
34
An isolated metal sphere of radius R, carrying an electric charge Q, is situated in the medium of relative permitivity, Er. A test charge is placed at a point p, distance r from the surface of the sphere. Let Eo represent the permitivity of free space. The electric potential at p is given by the expression
Trả lời
(B)
\(\frac{Q}{4 \pi E_o E_r (R +r)}\)
35
An isolated metal sphere of radius R, carrying an electric charge Q, is situated in the medium of relative permitivity, Er. A test charge is placed at a point p, distance r from the surface of the sphere. Let Eo represent the permitivity of free space. The magnitude of the electric field intensity at P is given by the expression
Trả lời
(D)
\(\frac{Q}{4 \pi E_o E_rR^2}\)
36
A resistor of resistance R is connected to a battery of negligible internal resistance. If a siilar resistor is connected in series with it the
Trả lời
(B)
total power dissipated is doubled
37
A cell of e.m.f. 1.5V is connected in series with a resistor of resistance 3.0\(\Omega\). A voltmeter connected across the cell registers 0.9V. Calculate the internal resistance of the cell
Trả lời
(A)
2.0\(\Omega\).
38
A wire of resistivity 4.40 x 10-5\(\Omega\) cm has a cross sectional area of 7.50 x 10-4 cm2. Calculate the length of the wire that will be required to make a 4.0\(\Omega\) resistor
Trả lời
(B)
68.18cm
39
A battery of e.m.f. 12.0V and internal resistance0.5\(\Omega\) is connected to 1.5\(\Omega\) and 4.0\(\Omega\) series resistor. Calculate the terminal voltage of the battery.
Trả lời
(B)
11.0V
40
If the direction of the curent in a straight wire is reversed, the magnetic field
