2022 Paper 2 (22/01/2025)

Question 1

Assumptions in deriving PV = 1/3 NM ( Crms ) ^ 2 ?

Answer 1

Volume of particles is negligible compared to the volume of the container. Collision time is negligible compared to the time between collisions. Collisions are elastic and kinetic energy is conserved. There are negligible forces between particles except for collisions.

Question 2

Using Newton’s Laws, why do molecules exert force on walls of container?

Answer 2

There is a change in momentum of the molecules at the wall as the direction changes and this is as a result of Newton’s 2nd Law. The force on the wall exerts a force on the molecule and this is due to Newton’s 3rd law.

Question 3

Effect of doubling temperature for an ideal gas?

Answer 3

This will cause double the volume and double the pressure leading to the curve on a pressure volume graph looking like its shifted to the right and up whilst having the same gradient of curve

Question 4

Electrons transferred to an initially uncharged sphere?

Answer 4

Excess electrons will move onto the outer surface and are equally spaced out due to electrons repelling each other

Question 5

Field lines identifying larger mass?

Answer 5

Greater mass is due to denser field lines and this is due to density of field lines depending on mass. If the field of one extends past half way would indicate that mass is larger. Null point is closer to other mass which means mass is larger

Question 6

Showing field direction on a point?

Answer 6

Draw a tangent from the particular point in direction towards mass for a gravitational field

Question 7

Area under gravitational field strength and distance graph?

Answer 7

Energy transferred otherwise the work done for an object of unit mass or 1kg and as well as this can be the change in gravitational potential

Question 8

Why can a smaller mass object not have a circular orbit around larger mass object?

Answer 8

A circular orbit does not follow a gravitational equipotential and the resultant force is not centripetal and contiual towards the larger mass object

Question 9

Function of core in a transformer?

Answer 9

A soft iron core guides magnetic field trhough secondary coil in order to maximimise magnetic flux through it. The greater flux linkage from the primary coil to secondary coild compared to an air core

Question 10

Function of secondary coild of transformer?

Answer 10

A conductor has a varying magnetic flux passing through it producing an induced EMF that is determined by the number of turns in the primary and secondary coil. Since EMF is induced by alternating field it means the secondary coil has more turns than primary coil it means its its EMF is higher than EMF in primary coil

Question 11

Efficiency of transformer increased with constructing core with iron sheets seperated by another material?

Answer 11

Core has been laminated with insulating sheets between layers of iron reducing energy loss trhough eddy currents. Since the sheets are insulating they are made from a hgih restivity material which reduces the eddy currents and the charge flowing in the core. The sheets also make smaller EMF’s be induced in the core. and the resistance is high which lowers the eddy currents.

Question 12

Why is a certain voltage used for long distance power transmission?

Answer 12

If voltage is too low then power is transmitted at a high current which results in energy loss through heating. If voltage is too high isolation issues are caused due to difficulty in isolating the current. A certain voltage is used to decrease current and energy loss through resistance rather than heat

Question 13

Binding energy of a nucleus?

Answer 13

Energy reuired to seperate nucleus into individual nucleons otherwise protons and neutrons. Energy given out when nucleus is formed from its individual nucleons otherwise protons and neutrons

Question 14

Escape Velocity Equation?

Answer 14

1/2 x mv^2 = GM1M2/r

Question 15

Consequence of smaller orbital radius but same mass and around same point?

Answer 15

The object with the smaller orbital radius will have a larger gravitational force, will travel faster which results in a greater speed, kinetic energy and a lower orbital period

Question 16

Phase difference between EMF and magnetic flux linkage?

Answer 16

90 degrees out of phase

Question 17

Existence of energy levels in nuclei?

Answer 17

This is due to existence of gamma radiation as it can only be emitted by nuclei since they have enough energy to emit gamma radiation

Question 18

Gamma radiation not making absorber radioactive?

Answer 18

Gamma radiation doesn’t make the nucleus unstable but instead just supplies the energy