H2 PHYSICS PRACTICAL

H2 CHEMISTRY PRACTICAL

H2 BIOLOGY PRACTICAL

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HOW TO BOOK A LAB SESSION:

(1) Decide which Program or Lab sessions you need or most suitable for, by visiting the webpages of the practical subjects you are interested in (if you can’t find the labs you need, message us at 87762711).

(2) Whatsapp or Message our staff at 87762711 with your Name, Private or School Candidate, A or O level, Subject or Lab Name (e.g Lab PP2), Date and Time of Lab. (Our staff will then guide you on how to register and make payment. If you are not sure about the lab sessions, just state your Name and the Subjects and we will get back to you)

(3) Register Online by clicking below:

(4) Pay Registration fee of $30 via Paynow or funds transfer.

(5) Make the required payment for each lab session at least 5 days before the date of the lab session. (You may also pay for several sessions at one go to ensure that you will have a place in future slots)

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Suggested Answers to 2015 A Level H2 Physics 9646 Paper 3

1a) 1. Net external force acting on the system is zero

2. Net torque on the system about any point is zero

bi) Equilibrium system. Ball is falling at constant speed, resultant force is zero.

ii) Not equilibrium. There is resultant force in the form of centripetal force on the satellite due to the earth. There is a constant change in direction therefore there is change in velocity.

2a) 6.33 x 10^7  m

b)Bright fringes get dimmer, dark fringes get brighter.

c)For interference pattern to be seen, a should be much smaller than d. When this condition is not met, fringes cannot be seen. When a becomes too large, the central maximun diffraction bands will not be wide enough to produce inteference pattern.

3a) 14.0ºC

b) With an increase in temperature, the resistance of the thermistor drops. This leads to a drop in the circuit’s total resistance which increases the current through the thermistor, increasing the heating on the thermistor and further lowering the resistance. When the resistance is too low, the whole process will continue and result in a thermal runway, resulting in the thermistor permanently damaged by heat.

4a) Tesla is a unit of magnetic flux density when a uniform magnetic field normal to a wire carrying a current of 1A produces a force per unit length of 1N/m

bi) Force acting on the particle is always normal to the velocity of the particle.

ii) 2.38 x 10^-21 Ns

c) *Line is downwards with a smaller curvature.

5a) A photon is a packet of energy of electromagnetic radiation

bi) 3.84 x 10^-19  J

ii) 8.36 x 10^-25  Ns

c) 52.4º

6ai) Rate of change of velocity

ii) Since the radius of earth is 6400km, several km above the earth’s surface would not affect the acceleration of free fall.

bi) Surface area of the ball is too small or distance traveled by the ball is too short.

ii) 1. 0.299 s

2. 0.0362 s

c) 9.8%

di) The height to fall has now been decreased, thus it takes less time for the ball to travel to the point.

ii) The ball will be affected by the magnetic force exerted onto it, thus reducing the net downward force acting on the ball. As a result, the time taken will be longer.

e) Acceleration will decrease till it reaches zero. When air resistance is equal to the weight of the ball, the resultant force acting on the ball will be zero. Hence it has reached terminal velocity and acceleration is zero.

7ai) 1. 24.04 V

2. 60.5 Hz

ii) There is a heating effect regardless of direction of the current. It depends on the root mean square current instead of the average current. The heating effect is caused by power loss.

bi) The amount of thermal energy required to raise the temperature of 1 unit mass of the substance by 1ºC

ii) This indicates the power loss from the system to the surrounding.

iii) 4.22 x 10^3  J/kg K

c) *same gradient, y-intercept should be more negative.

di) The increase in internal energy of a system is equal to the sum of the thermal energy supplied to the system and the amount of work done on the system

ii)If specific heat capacity is measured at a constant volume, no work is done on system. If specific heat capacity is measured at constant pressure, there will be a change in volume. Hence, there is work done on the gas.

8ai) An object undergoing oscillatory motion with its acceleration directly proportional to its displacement from its equilibrium position. The acceleration is always towards the equilibrium position.

ii) 1. Acceleration is always opposite in direction of displacement. Hence it is oscillating.

2. Acceleration is not directly proportional to its displacement. Hence, oscillations are not simple harmonic.

bi) 1. A wave in which the particles oscillates parallel to the direction of propagation.

2. The speed of the wave means the distance traveled per unit time by a wave front.

ii) 1. 1.20 x 10^-3

2. 1.20 x 10^-3

3. 3.20 x 10^-3  m/s

4. 2.71 x 10^-31  J

iii) Sound waves moves relatively fast in gas but the gas molecules oscillate back and forth about their original positions with relatively small speeds.

ci) Energy of the wave originates from the vibrational motion of the gas molecules.

ii) It is caused by the pressure imbalance from the disturbance of the gas’ uniform density.

 

 

A-LEVEL H2 MATH JUNE HOLIDAYS IN TENSIVE REVISION

A-LEVEL H2 PHYSICS JUNE HOLIDAYS INTENSIVE REVISION

 

JUNIOR COLLEGE / A-LEVEL TUITION:

H2 PHYSICS PRACTICAL

 

H2 CHEMISTRY PRACTICAL

 

H2 BIOLOGY PRACTICAL

 

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HOW TO BOOK A LAB SESSION:

(1) Decide which Program or Lab sessions you need or most suitable for, by visiting the webpages of the practical subjects you are interested in (if you can’t find the labs you need, message us at 87762711).

(2) Whatsapp or Message our staff at 87762711 with your Name, Private or School Candidate, A or O level, Subject or Lab Name (e.g Lab PP2), Date and Time of Lab. (Our staff will then guide you on how to register and make payment. If you are not sure about the lab sessions, just state your Name and the Subjects and we will get back to you)

(3) Register Online by clicking below:

(4) Pay Registration fee of $30 via Paynow or funds transfer.

(5) Make the required payment for each lab session at least 5 days before the date of the lab session. (You may also pay for several sessions at one go to ensure that you will have a place in future slots)

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Physics Paper 1 MCQ

1) A  2) D  3) C  4) A  5) C

6) A  7) D  8) C  9) A  10) C

11) B  12) A  13) D  14) A  15) A

16) A  17) C  18) A  19) C  20) B

21) C  22) D  23) B  24) B  25) A

26) B  27) B  28) B  29) D  30) B

31) B  32) D  33) B  34) C  35) C

36) C  37) C  38) A  39) D  40) B

 

Physics Paper 2

1. a) EPE = 0.662J

bi) The system has only GPE before the 300g mass is released. After releasing, part of the GPE is converted to KE and to EPE. At the lowest point, once the mass comes to a stop, all of the GPE will have been converted to EPE.

ii) v = 1.21 m/s

iii) 0.40m

2a) Select 2 points from the graph: (6.0, 1.25) and (12.0, 2.50)

(V – 12.0)/(I – 2.50) = (12.0 – 6.0) / (2.50 – 1.25)

V – 12.0 = (6.0/1.25) (I – 2.50)

V = 4.81I

V is proportional to I

bi) 4.8Ω

ii) 1.3 A ,  1.6A

iii) 6.35 V

3a) Incident photons must have energy greater than or equal to the work function of M to emit one electron. Energy of photon is related to the frequency of the electromagnetic radiation by E = hf

bi) Free electrons at the surface are emitted with maximum KE but electrons of the outer shell require more energy to escape thus they will be emitted with less KE. A minimum potential difference is present to stop the photoelectrons with the maximum KE from reaching the collector in order to reduce the current to zero.

ii)It is limited by rate of emission of photoelectrons, which is dependent on the intensity.

c) 9.45 x 10^14  Hz

d) Starts from -2.2v and follows the same shape of the original. The value of y-intercept is doubled due to the doubled intensity.

4a) 0.712 m/s^2

bi) Since the 2 moons move in circular orbits around Jupiter’s center of mass, thus the centripetal force is also the gravitational force due to Jupiter, which acts towards Jupiter’s center of mass.

ii) 2.33

5ai) 4.80 x 10^-14 N

ii) -2.30 x 10^-16 N

b) Electrostatic force on A due to B and B due to A are internal forces. They have the same magnitude but different in direction. Thus the resultant force action on the molecule is zero.

c) 1.6628 x 10^-25  Nm

6a) 128, 54

b) 1510 s

7ai) s = -3.0

ii) -3.170 , -0.693

iii) Plot the point and draw the best fit line.

iv) 3.10

v) There is a linear relationship between ln(y1/m) and ln(l/m) with a gradient of 3.1 and with a y- intercept of -1.02.

vi) 3

b) k = 2.70 x 10^-10

ci) Acceleration is directly proportional to the displacement. The negative sign indicates that the acceleration is opposite to the displacement and is always directed to the position of zero displacement.

ii) 0.560

8.

Apparatus.

Filament lamp, power supply, beaker, thermometer, Stirrer, Stopwatch, Voltmeter, Ammeter, Rheostat, Switch, Weighing machine, Waterproof tape.

Draw a diagram with a filament lamp immersed in water, with the thermometer and stirrer inside the beaker. Draw the circuit of the lamp with connecting ammeter and voltmeter and the power source.

Procedure.

1. Measure mass of water in beaker, m.

2. Insulate the beaker.

3. Connect filament lamp with circuit, wrap the metal cap with the waterproof tape.

4. Set up apparatus as shown.

5. Record initial temperature.

6. Close the circuit and start the stopwatch.

7. When the temperature hits 70ºC, stop the stopwatch and record the readings of the voltmeter and ammeter.

8. Repeat steps 5 to 7 after replacing the hot water in the beaker with the same amount of water at room temperature. Obtain different potential differences by changing the resistance of the rheostat.

Working

1. 1 – (Thermal energy/electrical energy output)

2. Relationship between I and t is given by η = aV^b , where a and b are constants. The equation can be written as lg η  = b lg V + lg a

3. Plot a graph of lg η against lg V and obtain a and b

Accuracy

1. Minimise heat loss to surroundings by using the lid and lagging.

2. Conduct preliminary experiments to decide on the suitable values of resistance and voltage supply.

3. Ensure experiment is not conducted over long periods of time so that efficiency of the lamp is not affected by the thermal energy released.

Safety

1. Handle with dry hands to prevent electrocution.

2. Ensure the circuit is not in contact with the water.

3. Handle the beaker with care when replacing the water.

 

 

 

A-LEVEL H2 MATH JUNE HOLIDAYS INTENSIVE REVISION

A-LEVEL H2 PHYSICS JUNE HOLIDAYS INTENSIVE REVISION

 

JUNIOR COLLEGE / A-LEVEL TUITION: