Paper 1 2021

Question 1

When can’t we use the young’s double slit equation

Answer 1

When slit separation(s) is comparable to the distance between slits and screen(D).
D must be much bigger than s to use youngs double slit

Question 2

What are decay equations for k+

What is decay for k-

Answer 2

K+ = pi+ + pi0

K+ = anti muon + muon neutrino

K- = pi- + pi0

Question 3

Is the linear velocity of 2 adjacent objects in circular motion the same?

Answer 3

Yes. It’s same when the collective centre of mass is at the midpoint of the distance between the 2 objects.

No. Not the same when the centre of mass is not at the midpoint.

Question 4

What is always the same for two adjacent objects in circular motion

Answer 4

The centripetal force on both objects
The angular velocity of both objects

Question 5

What happens to the angle of incidence when the optical fibre is bent

Answer 5

Angle of incidence becomes <critical angle.

So Total internal reflection stops occurring, therefore incident ray is REFRACTED at core-cladding boundary

Question 6

How to find uncertainty of a set of values

Answer 6

Range /2