S5 Mock Examination,2000-2001
Physics Paper I, p.1
S5 Mock Examination(2000-2001)
Physics ,Paper I
Date: 19/3/2001
1.
2.
3.
Time allowed:90 minutes
This paper consists of two sections, A and B.
Section A contains eight questions. Attempt ALL questions. Section B contains five questions.
Attempt any Four questions.
Some questions contain parts marked with an asterisk(*). In answering these parts, candidates are
required to give paragraph-length answers. In each of these parts, one mark is allocated to assess
candidates’ ability in effective communication.
4.
5.
6.
Take g= 10ms 2 .
Unless otherwise specified, all the cells are assumed to have negligible internal resistance.
The last page of this question paper contains a list of Physics formulae which you may find useful.
Section A. (40 marks)
Answer ALL questions.
1. A yellow light ray X enters a semi-circular glass block. Its refracted ray is shown below,
θ1
and θ 2 are measured and a graph of sinθ 2 versus sinθ 1 is shown below.
Use the graph to find
(a) the refractive index of the glass, ( 3marks)
(b) angle θ 1 when θ 2 = 90 0 . Give the name of this angle. (2 marks)
S5 Mock Examination,2000-2001
Physics Paper I, p.2
2. The ratings of an air-conditioner and a television-set are tabulated as follows.
Voltage
Power
Air-conditioner
200 V
2000W
Television-set
200 V
400W
(a) Find the working resistance of the air conditioner. (1 mark)
(b) Choose a suitable rating (2A, 5A,10A or 13A) for the fuse installed inside the air conditioner.
Explain your answers with calculations. (1 mark)
(c) Can these two appliances be connected to the same 13A socket and work together? Explain. (2
marks)
3. A bullet of mass 0.02 kg is fired horizontally from a gun. It is embedded into a stationary trolley of
mass 1 kg resting on a smooth table. The trolley then moves up a smooth inclined plane and it is
momentarily stationery after travelling 0.05 m up the inclined plane.
(a) Find the speed of the trolley, with the bullet inside, when it starts moving up the inclined
plane.(2 marks)
(b) Find the speed of the bullet when emitted from the gun. (2 marks)
4. You are provided with the components below.
(a) Using these components (and any necessary connecting wires), draw a circuit diagram to show
how electricity is supplied to the lamp by the a.c. power supply through a long distance. (3
marks)
(b) Explain the uses of the transformers in this circuit. (3 marks)
5.
In a ripple tank, the following wave pattern is observed.
(a) Explain what happens in the tank. ( 2 marks)
(b) How would you show that the wave frequency does not change ? ( 2marks)
(c) Find the ratio between the velocities of the two waves. (2 marks)
S5 Mock Examination,2000-2001
6.
Physics Paper I, p.3
A car is travelling at a uniform speed of 20 ms 1 . At time t = 0 s, the driver sees the traffic light at
40 m in front turn red. After a reaction time of 0.5 s, he applies the brakes to bring the car to rest at
t = 4 s with uniform deceleration.
(a) Draw the speed-time graph of the car, starting from the instant the driver sees the red light to
the instant the car stops. (2 marks)
(b) (i) Find the area under the graph. ( 1 mark)
(ii) Does the car stop in front of or beyond the traffic lights ? Explain your answer. (2 marks)
END OF SECTION A
Section B (60 marks)
Attempt any FOUR questions.
7. A pile of steel rods of total mass 2000 kg is lifted by a crane. The uniform arm AC, of mass 500 kg
and length 10 m, is kept in a horizontal position by a counter weight P. The rods are lifted with a
constant velocity of 0.1 ms 1 to a height of 20 m from the ground. The voltage and current of the
motor are 220 V and 15A respectively.
(a) Find the
(i) useful output energy,
(ii) input energy, and
(iii) efficiency
(2 marks)
(3 marks)
(2 marks)
of this crane.
(b) (i) What is the function of P in this crane? (1 mark)
(ii) If the steel rods are pulled horizontally towards B when the pulley is drawn to B by the motor,
in which direction should P be moved ?(1 mark)
(iii) Find the minimum weight of P so that AC can always be kept horizontal. ( 3 marks)
(c) If the steel rods are lifted with an acceleration of 1.5 ms 2 , find the tension of the wire. ( 3marks)
S5 Mock Examination,2000-2001
Physics Paper I, p.4
8. A student sets up an experiment to find the variation of the pressure P of air inside a flask with
temperature T. The following P-T graph is obtained.
(a) Draw a diagram to show a suitable experimental set-up and describe the procedure to obtain
the P-T graph. (5 marks)
(b) Explain why the temperature of air in this experiment cannot be greater than 100 0 C. (2 marks)
(c) (i) Find from the graph the absolute zero. ( 2 marks)
(ii) The flask is replaced by another one of equal volume but containing a greater mass of air
and the experiment is performed again. Copy the above graph on your answer book and sketch
the new P-T graph on the same graph. (3 marks)
*(d) Explain why the pressure of air decreases as the temperature drops based on the kinetic
theory of gases. (3 marks)
9. (a) (i) Explain with the help of diagrams what is meant by longitudinal and transverse waves.
(4 marks)
(ii) State one example of each type of waves, apart from waves on water and on stretched springs
and wires.
(2 marks)
(b) A wave is passed along a stretched wire. Figure a below shows how the displacement of one
particle in the wire varies with time. Figure b shows how the displacement of different particles
varies with distance along the wire at one particular time.
Use the information on both these graphs to find, for this wave,
(i) the amplitude,
(ii) the period, (iii) the wavelength, (iv) the speed.
(5 marks)
Figure a
Figure b
*(d) Figure c shows two loudspeakers, A and B, placed 1 m apart. The speakers are connected to the
same signal generator, which is set to give waves with a wavelength of 0.4 m.
What is heard at point X ? Explain.
(4 marks)
Figure c
S5 Mock Examination,2000-2001
Physics Paper I, p.5
10.
The sliding doors of an elevator has a light beam across them. The related control circuit is shown
above.
(a) (i) Give the names for the components X, Y and Z.
(ii) Name the logic gate involved. (4 marks)
(b) (i) When the light shines on X, its resistance is 80Ω. Calculate the potential at A if Y is adjusted to
120Ω.
(ii) When the light is blocked from X, its resistance rises to 600Ω. Calculate the potential at A
again. (3 marks)
(c) Construct a truth table for the logic gate L. (1 mark)
*(d) Explain why the door stops moving when the light is blocked . (4 marks)
(e) A student says that if the variable resistor is wrongly adjusted , the door will continue to close even
when the light is blocked. State whether this statement is correct or not and explain why. ( 3marks)
11. (a) In nature, a radioactive nucleus decays in a series. The following table shows parts of a series
from A to E.
Nucleus
A
B
C
D
E
Mass No.
238
Atomic No.
Emission
α
Half-life
4.56x 10 9 years
90
24.5 days
91
68 seconds
234
2.7x 10 5 years
230
α
8 x 10 4 years
(i) Copy the first four columns of the table and complete the missing items. (4 marks)
(ii) How long does it take for 87.5% of A to decay ? (2 marks)
(iii) Among the above five nuclei, which one do you think is the rarest nucleus in nature. Give
your reason. (2 marks)
(iv) Find the number of (1) protons, (2) neutrons in the nucleus of D. (2 marks)
(b) Carbon-14 isotope is a β-emitting source with a half-life 5700 years. In living tissue, we find
eight carbon-14 atoms in 10 13 atoms of carbon. In an antique table, we find that there are only
two carbon-14 atoms in 10 13 carbon-atoms. Estimate the age of the antique table.(3 marks)
*(c) Give two reasons why carbon is used for antique dating. (2 marks)
END OF PAPER
Setter:
S5 Mock Examination,2000-2001
Physics Paper I, p.6
Useful Formulae in Physics
(a) Relationships between initial velocity u, uniform acceleration a, final velocity v and displacement
travelled s after time t:
v = u + at
S= ut +
1 2
at
2
v 2 = u 2 + 2as
(b) Potential energy gained by a body of mass m when raised through a height h is mgh.
(c) Kinetic energy of a body of mass m moving with speed v is
(d) Power = force x velocity
(e) Equivalent resistance of two resistors R 1 and R 2 :
(i) in series = R 1 + R 2
(ii) in parallel =
R1 R2
R1  R2
(f) Power = potential difference x current
1
mv 2 .
2