IGCSE Physics

### CIE IGCSE Physics Solved Past Paper May/June 2020 P43

1 a(i) acceleration = (v-u)/t
b(i) constant acceleration
(ii) increasing acceleration
(iii) deceleration
(iv) constant speed
2a) mass = density*volume Volume = 0.30.30.4=0.036m3 Mass = 10200.036=37kg
bi) pressure due to depth = 500k-100k=400k Pa
Depth = pressure/(density*gravity) =400000/102010
=39m
(ii) force = pressure*area = 500*0.62 =3.110^4N

3a) Line of action of center of mass falls out of base of bus b) Less stable as center of mass of bus falls out of base of bus c (i) Mass of passengers = 7365=4745
Total mass = 4745+1600=21000kg
(ii) Force = mass*acceleration 2074514/20
= 15000N

4a) More energetic molecules escape from the surface leaving behind less
energetic molecules. Average kinetic energy of liquid decreases and as a
result temperature of remaining liquid drops
b) More wind, higher temperature of air

5a(i) Energy = power*time = 50260 = 6000J (ii) specific heat capacity = 6000/0.5513= 840J/kg (iii) Some heat from heater lost to surroundings so actual value might be
lower.
b) Water has higher specific heat capacity and since same rate of energy
is supplied to both sand and sea, Increase in temperature is not as much
that of the sand.

6a) With normal perpendicular to surface, angle of incidence = angle of
reflection
c) 1500m/s

7a) Angle of incidence = angle between normal and the incident ray. So angle of incidence = 90-40=50
Refractive index = sin i/sin r
Sin r =sin i/n
r = sin-1(0.32) = 18
b) When all the light travelling from an optical denser medium to an
optically rarer medium is reflected for which the angle of incidence is
greater than the critical angle.
c) Light reflected from surface one as angle of incidence is greater than
critical angle. Light from surface 2 bends away from normal as it is travelling from a denser to rarer medium.

8 a(i) Electric field is the area where a charge experiences a force
(ii) It is the direction of charge on a positive charge
b) The ball after moving first touches either of the plates in case it touches
the positive plate, it gains positive charge through the layer of conducting metal on its surface. It is then repelled away from the positive plate and towards the negative plate.
c) Charge = current*time
time = charge/current
= 15/0.29 = 52 seconds

9 a(i) In this question Flemingâ€™s Left Hand rule is applied so by having the
pointer finger, middle finger and the thumb in perpendicular positions to each other, pointer indicates magnetic field with the middle finger indicating the conventional current direction, the thumb represents. Direction of force, which is downward on left side of coil. This means the coil turns anti-clockwise.
(ii) from negative to positive terminal
(iii) electrons repelled from the negative terminal of supply
b(i) turns in opposite direction
(ii) turns faster
(iii) turns faster

10 a(i) Beta particle
b (i) Background radiation of rock
(ii) 11400/5700 = 2 half lives have passed so that means after subtracting
background radiation from 80 and 20, counts are 70 and 10. This means that if statement of question is right, after reducing 70 by half twice(because two half lives) the amount should be around 10 but:
70/2=35/2=17.5>10 as this amount is greater than that suggested by
question, this means that age of sample is more than 11400 years as it
needs more than just 2 half lives to decrease from 70 to 10.