The leaves of many plants have stomata that show a regular daily rhythm of opening and closing
over a period of 24 hours.
(a) Explain why it is important for plants to open and close their stomata in a daily rhythm.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [3]
(b) Fig. 2.1 shows the results of an experiment to monitor this rhythm over three days and nights
for the plant Arabidopsis thaliana. The percentage of open stomata is shown. Each day
consisted of 14 hours of light (white bar) and each night consisted of 10 hours of darkness
(black bar).
100
Key
day
open night
stomata 50
/ %
(cid:44)(cid:1)(cid:1)(cid:1)(cid:1)(cid:9)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:2)(cid:2)(cid:44)
(i) Determine the amplitude, in cm, of the oscillations.
amplitude = ....................................................cm [1]
(ii) Show that the angular frequency of the oscillations is 3.2 rad s–1.
[2]
(iii) Calculate the period T of the oscillations.
T = .......................................................s [2]
(iv) On Fig. 4.3, sketch the variation of h with time t from t = 0 to t = 6.0 s.
(cid:44)(cid:1)(cid:1)(cid:1)(cid:1)(cid:9)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:4)(cid:44)
(b) Fig. 1.2 shows an action potential in a rat neurone and Fig. 1.3 shows an action potential in a
snail neurone.
rat snail
The leaves of many plants have stomata that show a regular daily rhythm of opening and closing
over a period of 24 hours.
(a) Explain why it is important for plants to open and close their stomata in a daily rhythm.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [3]
(b) Fig. 2.1 shows the results of an experiment to monitor this rhythm over three days and nights
for the plant Arabidopsis thaliana. The percentage of open stomata is shown. Each day
consisted of 14 hours of light (white bar) and each night consisted of 10 hours of darkness
(black bar).
100
Key
day
open night
stomata 50
/ %
(a) Define specific heat capacity.
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [2]
(b) Two solid blocks X and Y are made from different metals. The blocks have different initial
temperatures. Block Y is initially at room temperature.
The blocks are placed in direct thermal contact with each other at time t = 0. Fig. 2.1 shows
the variation with t of the temperatures of the two blocks.
100
Question
Physics
CAIE2024
(a) State what is meant by simple harmonic motion.
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [2]
(b) A block is suspended from a spring, as shown in Fig. 4.1.
spring
block
h
floor
Fig. 4.1
The block is pulled down and released at time t = 0. It then oscillates vertically with simple
harmonic motion.
Fig. 4.2 shows the variation of the velocity v of the block with height h of the base of the block
above the floor.
(a) (i) State what is meant by rectification of an alternating voltage.
...........................................................................................................................................
..................................................................................................................................... [1]
(ii) State the difference between half-wave rectification and full-wave rectification.
...........................................................................................................................................
...........................................................................................................................................
..................................................................................................................................... [2]
(b) (i) Complete Fig. 6.1 to show a circuit that produces half-wave rectification of an alternating
input voltage V to produce output voltage V across the resistor R.
IN OUT
V C R V
IN OUT
Fig. 6.1
[2]
(ii) State the purpose of the capacitor C in the circuit of Fig. 6.1.
...........................................................................................................................................
..................................................................................................................................... [1]
(c) The input voltage V in Fig. 6.1 is a square wave. Fig. 6.2 shows the variation of V with
IN IN
time t.
+12
V / V
IN
100 200 300 400 500 600
Time / s
(i) Calculate the acceleration of the train as it accelerates to a speed of
360 km hour–1.
(3)
...................................................................................................................................................................................................................................................
...................................................................................................................................................................................................................................................
...................................................................................................................................................................................................................................................
...................................................................................................................................................................................................................................................
...................................................................................................................................................................................................................................................
Acceleration of train =
.......................................................
*P74468A02024*
Question
Physics
CAIE2024
Fig. 5.1 shows a pendulum consisting of a metal sphere suspended by a thin string.
thin string
metal sphere
oscillations
Fig. 5.1 (not to scale)
The sphere undergoes small oscillations about its equilibrium position. The oscillations may be
considered to be simple harmonic.
Fig. 5.2 shows the variation with time t of the displacement x of the sphere from its
equilibrium position.
(a) State what is meant by the frequency of an alternating current.
...................................................................................................................................................
............................................................................................................................................. [1]
(b) An alternating current I in a resistor of resistance 680 Ω varies with time t according to
I = 3.5 sin (40πt)
where I is in A and t is in s.
(i) Show that the period of the alternating current is 50 ms.
[1]
(ii) On Fig. 8.1, sketch the variation of I with t between t = 0 and t = 100 ms.
(a) Define specific heat capacity.
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [2]
(b) Two solid blocks X and Y are made from different metals. The blocks have different initial
temperatures. Block Y is initially at room temperature.
The blocks are placed in direct thermal contact with each other at time t = 0. Fig. 2.1 shows
the variation with t of the temperatures of the two blocks.
100
Question
Physics
CAIE2024
(a) (i) State what is meant by rectification of an alternating voltage.
...........................................................................................................................................
..................................................................................................................................... [1]
(ii) State the difference between half-wave rectification and full-wave rectification.
...........................................................................................................................................
...........................................................................................................................................
..................................................................................................................................... [2]
(b) (i) Complete Fig. 6.1 to show a circuit that produces half-wave rectification of an alternating
input voltage V to produce output voltage V across the resistor R.
IN OUT
V C R V
IN OUT
Fig. 6.1
[2]
(ii) State the purpose of the capacitor C in the circuit of Fig. 6.1.
...........................................................................................................................................
..................................................................................................................................... [1]
(c) The input voltage V in Fig. 6.1 is a square wave. Fig. 6.2 shows the variation of V with
IN IN
time t.
+12
V / V
IN
Question
Physics
CAIE2024
(cid:44)(cid:1)(cid:1)(cid:1)(cid:1)(cid:9)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:2)(cid:2)(cid:44)
(i) Determine the amplitude, in cm, of the oscillations.
amplitude = ....................................................cm [1]
(ii) Show that the angular frequency of the oscillations is 3.2 rad s–1.
[2]
(iii) Calculate the period T of the oscillations.
T = .......................................................s [2]
(iv) On Fig. 4.3, sketch the variation of h with time t from t = 0 to t = 6.0 s.
A toy car moves up a slope at a constant speed, as shown. The car is moved by a motor
with a power output of 5.2 W. The car gains a gravitational potential energy of 0.40 J in
a time of 1.1 s.
Which of the following expressions gives the work done, in J, against resistive forces?
A 5.2 − (0.40 × 1.1)
B (5.2 × 1.1) − 0.40
C (5.2 ÷ 1.1) + 0.40
D (5.2 × 1.1) + 0.40
(Total for Question 3 = 1 mark)
*P74468A0224*
Question
Physics
CAIE2024
(a) State what is meant by simple harmonic motion.
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [2]
(b) A block is suspended from a spring, as shown in Fig. 4.1.
spring
block
h
floor
Fig. 4.1
The block is pulled down and released at time t = 0. It then oscillates vertically with simple
harmonic motion.
Fig. 4.2 shows the variation of the velocity v of the block with height h of the base of the block
above the floor.
Question
Physics
Edexcel2024
An object was thrown so that it followed the path shown. Assume drag forces
were negligible.
The object was thrown with an initial vertical component of velocity u. The time taken
to reach maximum height is t.
Which of the following could not be used to determine the maximum vertical height s
reached by the object?
Question
Biology
CAIE2024
(cid:44)(cid:1)(cid:1)(cid:1)(cid:1)(cid:9)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:4)(cid:44)
(b) Fig. 1.2 shows an action potential in a rat neurone and Fig. 1.3 shows an action potential in a
snail neurone.
rat snail
Question
Physics
Edexcel2024
0 × 106 V m−1 and the air becomes conducting for a short time.
(i) Calculate the minimum potential difference across the plates for sparks to
be created.
distance between parallel plates = 2.0 mm
(2)
...................................................................................................................................................................................................................................................
...................................................................................................................................................................................................................................................
...................................................................................................................................................................................................................................................
Minimum potential difference =
.......................................................
(ii) Explain why the voltmeter reading decreases significantly whenever sparks
are produced.
(3)
...................................................................................................................................................................................................................................................
...................................................................................................................................................................................................................................................
...................................................................................................................................................................................................................................................
...................................................................................................................................................................................................................................................
...................................................................................................................................................................................................................................................
...................................................................................................................................................................................................................................................
(Total for Question 15 = 10 marks)
*P74468A01324*