The force between molecules of the same substance is termed
Απάντηση
(C)
cohesive force
2
A net force of magnitude 0.6N acts on a body of mass 40g, initially at rest. Calculate the magnitude of tire resulting acceleration.
Απάντηση
(D)
15ms-2.
3
Palm oil from a bottle flows out more easily after it as been heated because the
Απάντηση
(B)
friction between oil layers is reduced
4
A body weighing 100N moves with a speed of 5ms-1 in a horizontal circular path of radius 5m. Calculate the . magnitude of the centripetal force acting on the body. (g = 10ms-2)
Απάντηση
(B)
50N
5
A motorcyclist, passing a road junction, moves due west for 8 s at a uniform speed of 5ms-1. He then moves due north for another 6 s with the same speed. At the end of the 6s his displacement from the road junction is 50m in the direction of
Απάντηση
(C)
N53oW
6
The time rate of change of displacement is known as
Απάντηση
(B)
velocity
7
A stone of mass 0.7kg is projected vertically , upwards with a speed of 5ms-1. Calculate the maximum height reached. (Take g as 10ms-2 and neglect air resistance)
Απάντηση
(B)
1.25m
8
If the force of attraction between the sun and the 1 planets is removed; the planets will
Απάντηση
(D)
continue to move perpendicular to their original orbits. '
9
A 15kg mass, suspended from a ceiling, is pulled aside with a horizontal force, F, as shown in the diagram above. Calculate the value of the tension, T. (g = 10ms-2)
Απάντηση
(B)
173.2N
10
A pendulum bob executing simple harmonic motion has 2cm and 12Hz as amplitude and frequency respectively. Calculate the period of the motion.
Απάντηση
(C)
0.08s
11
A trolley of mass 4kg moving on a smooth horizontal platform with a speed of 1.0ms-1 collides perfectly with a stationary trolley of the same mass on the same platform. Calculate the total momentum of the two trolleys immediately after the collision.
Απάντηση
(C)
4.0Ns
12
The ice point of an ungraduated mercury-in-glass thermometer is X, while its steam point is 90o. This thermometer reads 60o when the true temperature is 40oC Calculate the value of X.
Απάντηση
(C)
40o
13
Iron at 30oC feels colder to the hand than wood at 28oC because
Απάντηση
(D)
iron conducts heat more quickly from the hand than wood
14
An iron rod of length 50m and at a temperature of 60oC is heated to 70oC. Calculate its new length. (Linear expansivity of iron = 1.2 x 10-5K-1)
Απάντηση
(A)
50.006m
15
The heat capacity of a substance is the energy
Απάντηση
(B)
required to raise the temperature of the substance by one degree
16
The temperature of a piece of metal of mass 9 g is raised from 10oC to 110oC when it absorbs 108J of heat energy. Determine the specific heat capacity of the metal in J kg-1K-1
Απάντηση
(C)
120.0
17
Which of the following statements is not correct?
Απάντηση
(D)
The vacuum space in a flask helps to reduce heat loss by radiation.
18
Calculate the heat energy required to change 0.1kg of ice at 0oC to water boiling at 100oC. (Specific heat capacity of water = 4200 J kg-1K-1) (Specific latent heat of fusion of ice = 336,000 J kg-1)
Απάντηση
(A)
75,600J
19
Which of the following statements about evaporation is not correct?
Απάντηση
(D)
Evaporation takes place inside a liquid.
20
Calculate the power rating of an immersion heater used for 10 minutes to increase the temperature of 10kg of water by 15K. (Specific heat capacity of water = 4200 J l-1K-1)
Απάντηση
(A)
1,050W
21
A ray of light is incident on 'a plane mirror at an angle of 20o. This mirror is rotated through, twice this angle, In this new position the angle between the incident ray and the reflected ray is
Απάντηση
(D)
120o.
22
The air column in a resonance tube is set into resonance by a vibrating tuning fork. The resultant waves in the air column will be
Απάντηση
(D)
stationary and longitudinal.
23
The image of an object is located 6cm behind a convex mirror. If its magnification is 0.6, calculate the focal length of the mirror
Απάντηση
(D)
-15.00cm
24
The refractive index of glass for yellow light is greater than that for red light because yellow light
Απάντηση
(A)
has a greater amplitude than red light
25
The real image of an object formed by a converging lens of focal length 15cm, is three times the size of the object. Calculate the object distance
Απάντηση
(C)
20cm
26
Which of the following statements is not correct about long sight?
Απάντηση
(D)
The defect is corrected by using a diverging lens.
27
The amplitude of a wave is the
Απάντηση
(C)
maximum displacement of the wave particle from the equilibrium position
28
ln order to obtain a sound note of a high pitch from a wire stretched by a constant tension, the wire must be
Απάντηση
(B)
short and thin
29
If the position of resonance in a resonance tube is 16.50cm from open end of the tube, calculate the distance from the open end to the next position where resonance occurs. (Neglect end-correction)
Απάντηση
(D)
49.50cm
30
Thunder is usually heard some seconds after lightning is observed because
Απάντηση
(D)
light travels faster than sound
31
Using the data on the diagram above, calculate the potential difference across the 20- Ω resistor. (Neglect the internal resistance of the cell)
Απάντηση
(D)
60V
32
Using the diagram above, calculate the effective capacitance of the circuit
Απάντηση
(A)
1.56μf
33
The parts of a bar magnet at which the magnetic effect is strongest are called the
Απάντηση
(A)
poles
34
A resistance wire of length 2 m and of uniform cross-sectional area 5.0 x 10-7 m2 has a resistance of 2.2 Ω Calculate its resistivity
Απάντηση
(B)
5.5 x 10-7Ωm
35
Magnetic flux density is defined as the
Απάντηση
(B)
number of magnetic lines of force per unit area normal to the magnetic field
36
The voltage and current in the primary of a transformer are 200V and 2Arespectively. lf the transformer is used to light ten 12 V, 30 W bulbs, calculate its efficiency.
Απάντηση
(C)
75%
37
In a uniform electric field, the magnitude of the force on a charge of 0.2 C is 4N. Calculate the electric field intensity
Απάντηση
(A)
20 N C-1
38
A 10 Ω coil takes 21 s to melt 10g of ice at 0ºC. Assuming no heat losses, determine the current in the coil. (Specific latent heat of fusion of ice = 336 Jg\(^{-1}\))
Απάντηση
(C)
4A
39
A point charge of magnitude 2μC is moved through a distance of 0.02 m against uniform field of intensity 25 Vm-1 Calculate the work done on the charge
Απάντηση
(B)
1.0 x10-6J
40
Bohr’s atomic model proves most successful for the explanation of the. I. structure of the hydrogen atom; II. line spectra of the hydrogen atom; III. Multi-electron atoms. Which of the statements above is/are correct?
Απάντηση
(C)
I and II only
41
The diagram above illustrates the energy transitions of five electrons of an atom. Which of the transitions will produce the emission of longest wavelength?
Απάντηση
(A)
I
42
Which of the transitions will produce the emission of highest frequency?
Απάντηση
(A)
V
43
I. All elements emit and absorb characteristic spectra. II. Spectral analysis is an important method of identifying environmental pollutants. III. The chemical composition of stars could be determined using spectral analysis. Which of the statements above are correct?
Απάντηση
(A)
I, II and III
44
A metal has work function of 4.375 eV Calculate its threshold frequency. (h = 6.6 x 10-34Js; 1eV = 1.6 x 10-19J)
Απάντηση
(B)
1.06x1015Hz
45
The half-life of a radioactive substance is
Απάντηση
(D)
the length of time during which the activity of the substance reduces by 50%.
