Measurement of mass by using equal-arm beam balance uses the principle of
A.conservation of momentum.
B.conservation of energy
C.moments
D.gravitational pull of the earth
E.conservation of matter.
13.1 mark
A transistor is a device which
A.amplifies alternating current or voltage
B.amplifies direct current or voltage
C.rectifies direct current or voltage
D.amplifies and rectifies alternating current or voltage
E.rectifies alternating current or voltage.
14.1 mark
What causes water tides in the sea?
A.Rotation of the earth about the sun
B.Rotation of the moon about the earth
C.Rotation of the earth about its axis
D.Gravitational force due to the earth on the sea
E.Gravitational force due to the moon on the sea.
15.1 mark
Which is an incorrect statement about the solar planets?
A.They are always moving in space
B.They are all non-luminous
C.They all revolve round the sun as their centre
D.They all have at least one moon
E.The brightest planet as observed from the earth is venus.
Section B
2.2 marks
Using Newton’s second law of motion, state two quantities which vary with net force applied on a body.
(a)
State two quantities which vary with net force applied on a body.
2 mk
(b)
Write an equation obtained by combining the force and the two quantities you have mentioned.
2 mk
(c)
Evaluate the proportionality constant if your equation is used to define the unit of force, the Newton, while taking a unit of each variable in your equation.
1 mk
(d)
A certain force gives a mass m an acceleration of $12.0 \text{ m/s}^2$. What acceleration will the same force give the two masses when they are joined together?
4 mk
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3.1 mark
State Boyle’s law.
(a)
State Boyle’s law.
1 mk
(b)
Sketch the graph of pressure (p) against the reciprocal of volume (1/v) for air at constant temperature.
2 mk
(c)
A bubble of air of volume $50.0 \text{ mm}^3$ is released by a diver at a depth where the pressure is $304.0 \text{ cm Hg}$. Assuming the temperature remains constant, what is its volume just before it reaches the surface where the pressure is $76.0 \text{ cm Hg}$?
3 mk
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4.1 mark
Explain what is meant by ‘beats’ as applied to sound.
(a)
Explain what is meant by ‘beats’ as applied to sound
1 mk
(b)
Briefly explain how beats are formed.
2 mk
(c)
A vibrating string is sounded with a 288 Hz tuning fork and 3 beats are counted per second. The string is then loaded with small amount of plasticine and 2 beats are counted per second.
6 mk
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5.2 marks
Give two differences between a primary and a secondary cell .
(a)
Give two differences between a primary and a secondary cell .
2 mk
(b)
Six cells each of 2.0V and internal resistance 2.0Ω are connected in two groups of three in series, the two groups are then connected in parallel to an external resistor of 30.0Ω.
7 mk
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6.3 marks
Name two objects in space which are the earth’s nearest neighbours.
(a)
Name two objects in space which are the earth’s nearest neighbours.
2 mk
(b)
What are the real names of objects in the sky which are commonly known by the following names?
3 mk
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Section C
7.8 marks
A piston of small cross section area of 30.0 cm$^2$ is used in hydraulic press to exert a force of 300.0 N on the enclosed liquid. A connecting pipe leads to a large piston of cross section area 600.0 cm$^2$. Find
(a)
State Pascal’s principle of transmission of pressure.
1 mk
((b)(i)
the mechanical advantage (MA) of the pistons of the press.
2 mk
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8.10 marks
If the speed of light in air is $3.0 \times 10^8$ m/s and the wavelength, $\lambda$, of yellow light in air is $5.89 \times 10^{-7}$ m, calculate:
((a)(i)
Explain how the refractive index is related to the velocities in two different adjacent media when refraction of light occurs between them. Hence deduce the relation between refractive index and the wavelengths in the two media.
2 mk
((b)(i)
the wavelength, $\lambda_s$, of yellow light in sulphur of refractive index 1.96.
3 mk
(c)
What causes light to refract when it passes through two adjacent media of different densities?
1 mk
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9.9 marks
(a)
What is meant by magnetic materials? Give two examples.
3 mk
(b)
State the law of magnets.
1 mk
(c)
Explain with an illustration how one can locate the position of a north-pole of a bar magnet.
3 mk
(d)
Explain with an illustration how to magnetize a steel bar using electric current.
3 mk
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10.3 marks
Why is the iron core made of laminations instead of being in one solid piece?
((a)(i)
Why is the iron core made of laminations instead of being in one solid piece?
1 mk
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11.2 marks
Write two pairs of isotopes from the above series.
((b)(i)
Identify the type of particle emitted in the following stage: $\frac{228}{90}Th \longrightarrow \frac{224}{88}Ra$
1 mk
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12.4 marks
An output of a transformer is connected in series with a semiconductor diode
((c)(i)
Give a reason whether this device is suitable or not for use in a radio.
2 mk