MockPhysicsRevision

Question 1

The equation to calculate resistance is:

Answer 1

Resistance= potential difference/ current
R=V/I

Question 2

Explain why the count rate was less than the activity of the sample of lanthanum-140: (2)

Answer 2

The radiation spreads out in all directions.
So only some radiation goes into the GM tube.

Question 3

Explain why the teacher stood as far away from the apparatus as possible

Question 4

CALCULATION QUESTION
(TEMPORARY)
Explain how the count rate was not inversely proportional to thickness of the lead in the practical: (3)

Answer 4

a calculation of the product of
thickness and count rate
a second calculation of the
product of thickness and count
rate
a comparison of the calculated
values and a recognition that
they are different

Question 5

CALCULATION QUESTION
(TEMPORARY)
Determine the ratio of cerium atoms when it was 100 seconds old compared to 350 seconds old:
(4)

Answer 5

half-life = 50 seconds
250 seconds difference in age =
5 half lives
ratio= 1:32

Question 6

Explain how motion of the air molecules caused pressure to change as temperature decreased in a container: (3)

Answer 6

pressure decreased

because molecules have less
kinetic energy

so fewer collisions (with the
wall/container each second)