PAPER 2

Question 1

When a plastic rod is rubbed with a cloth, the plastic rod gains ……………………………………………………..

After the plastic rod has been rubbed with the cloth, the plastic rod has a …………………………………………………….. charge.

Answer 1

• Electrons
• Negative charge

Question 2

Answer 2

• (droplets) repel each other
• (droplets) spread out / finer spray

Question 3

Droplets of paint are positively charged. The object being painted is given a negative charge. Explain why this is an advantage.
(2)

Answer 3

• (object) attracts droplets
• paint reaches back of object
• less paint wasted

Question 4

As the sweat evaporates, it cools his body. Use ideas about particles to explain why evaporation leads to cooling. (3)

Answer 4

• evaporation as liquid turns into gas
• higher KE
• reducing (average) energy of particles left
• reducing temperature;

Question 5

Suggest why a runner might cool down too quickly if he does not wear a foil sheet. (2)

Answer 5

• (still covered in) sweat /evaporation mentioned;
• not generating as much ‘new’ heat;

Question 6

Explain how the foil sheet reduces heat loss. (2)

Answer 6

• (shiny) surface reflects/poor absorber
• reducing radiation /IR losses;

Question 7

How could the student check that the ruler is horizontal? (2)

Answer 7

• place spirit level on ruler
• bubble should be central;

Question 8

Answer 8

• clockwise and anticlockwise moments equal
• fish are closer to A;
• therefore to get same moment for smaller distance (force must be larger);

Question 9

State one advantage of transmitting electricity at high voltages. (1)

Answer 9

• (lower current leads to)
• less power losses

Question 10

Some power stations use uranium as a fuel. Describe the problems that arise from the disposal of waste from this type of power station. (4)

Answer 10

• Radioactive / emits radiation
• High activity
• Long half life
• causes harm to people /environmen
• Expensive to dispose of
• Need for security / shielding
• location of storage is tough to find

Question 11

Answer 11

• at lower temp, particles move at lower kinetic energy on average
• so hit sides less often / with less energy
• reducing force / pressure
• increased tension in rubber
• pulls balloon material into smaller size;

Question 12

State what is meant by the term magnetic field line. (1)

Answer 12

Line that shows direction of the magnetic force/field

Question 13

The student wants to find the density of the coin. She uses her values for the diameter and thickness of the coin to calculate its volume. What else must she do to find the density of the coin? (3)

Answer 13

• Measure/find mass
• Using electronic balance
• Repeat readings, find average
• Density = mass/volume
• kg/m3

Question 14

The washing machine is fitted with a fuse rated at 13 A. Explain why the washing machine is fitted with a fuse. (2)

Answer 14

• As a safety device
• In case of fault
• excessive current
• Prevents (wires or appliance) overheating/fire

Question 15

Why does falling over reduce the gravitational potential energy of the carton? (1)

Answer 15

Centre of gravity is lower

Question 16

Explain why alpha particles and beta particles have different penetrating powers. (5)

Answer 16

• alpha particles have less penetrating power /less range
• alphas have more charge
• alphas cause more ionization
• alphas have more mass
• slowing force on alpha particles is larger
• kinetic energy of alpha lost quickly causing ionization
• larger alpha particles are more likely to collide with atoms