A tuber of cassava can be processed into powder. This explains the face that
Trả lời
(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
Trả lời
(C)
48N
3
The tendency of a body to remain at rest when a force is supplied to it is called
Trả lời
(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
Trả lời
(D)
10.0N
5
A moving object is said to have a uniform acceleration if its
Trả lời
(C)
velocity increases by equal amount in equal time intervals
6
The period of an oscillatory motion is defined as the
Trả lời
(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
Trả lời
(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
Trả lời
(B)
10.0kgms-1
9
Which of the following statements correctly defines a simple machine? a device
Trả lời
(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.
Trả lời
(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\(^{-1}\)]
Trả lời
(B)
3mm
12
The heat capacity of a calorimeter is the amount of energy required to
Trả lời
(C)
change the temperature of the calorimeter
13
Which of the following statement about latent heat of vaporization is correct? It
Trả lời
(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
Trả lời
(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.
Trả lời
(D)
30.75cm3
16
A wave of weight length 0.30m travels 900m in 3.0s, calculate its frequency
Trả lời
(C)
1000Hz
17
Which of the following condition is necessary for the occurrence of total internal reflection of light?
Trả lời
(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
Trả lời
(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
Trả lời
(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
Trả lời
(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
Trả lời
(B)
1.35m
22
A converging lens has a focal length of 5cm. Determine its power
Trả lời
(A)
+20.0
23
Which of the following pairs of rays shows the widest separation in the spectrum of white light?
Trả lời
(B)
orange and indigo
24
Which of the following statements about the human eye and the camera is correct?
Trả lời
(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
Trả lời
(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
Trả lời
(B)
100.0ms-1
27
Which of the following instruments gives a pure note when sounded?
Trả lời
(C)
tunning fork
28
Which of the following features of an electrostatic line of force is not correct?
Trả lời
(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 ?
Trả lời
(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
Trả lời
(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
Trả lời
(B)
1.00A
32
Which of the following factors does not affect the the electric resistance of a wire?
Trả lời
(B)
mass
33
A current of 10A passes through a conductor for 10s, calculate the charge flowing through the conductor
Trả lời
(A)
100.0C
34
A lamp is rated 240V 60W, calculate the resistance of its filament
Trả lời
(C)
960\(\Omega\)
35
The maximum power dissipated by a 100\(\Omega\) resistor in a circuit is 4W. Calculate the voltage across the resistor
Trả lời
(B)
20V
36
One difference between a reactance and a resistance in an alternating current circuit is
Trả lời
(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?
Trả lời
(D)
Lenz's law
38
Which of the following statements about an electromagnet is not correct?
Trả lời
(D)
it has permanent poles
39
Which of the following statements is not true of the isotopes of an element? They
Trả lời
(D)
have the same mass number
40
Which of the following statements is true of ultra violet radiations? It
Trả lời
(C)
is an electromagnetic wave
41
A radioactive element has a decay constant of 0.077s-1, calculate its half life
Trả lời
(B)
9.0s
42
The minimum energy required to remove an electron from an atom is known as
Trả lời
(B)
ionization energy
43
Nuclear fission is preferred to nuclear fusion in the generation of energy because?
Trả lời
(A)
very high temperature are required for fusion
44
Which of the following reactions represents nuclear fusion?
Trả lời
(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?
