Physicss A2 common mistakes questions (ALL TOPICS)

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Describe the current standard model.

The standard model states that all matter is composed of two main types of funamental particles, quarks and leptons.

The baryons are made up of three quarks or anti quarks. And mesons are made up of quark and anti-quark. Baryons can have a charge positive or negative 1. Baryons have a baryon number 1, and lepton number 0. The standard model has 6 leptons, their lepton number is 1 but baryon number is 0.

Find initial K.e using 1/2mv²
find k.e through 60 tubes, 60 x V x Q (W = N x V x Q)

Sum both
Final ans: 7.68×10^-13.

How are standing waves produced?

Progressive wave travels along the medium and meets at the boundary. When they reflect they interfere. The waves meet in anti-phase (n + 1/2) and interfere destructively and form nodes.

May 2025

Explain how Lenz’s law applies to the motion of the coil. (2)

(By Lenz’s law) the direction of the induced e.m.f. is such as to oppose the change in magnetic flux
Accept cutting of magnetic flux
Accept opposing the change producing it.

There is a force opposing the movement of the coil

2) Determine the potential energy of the electron as predicted by the Bohr model. (3)

4.3 ×10−18 J (1)
27.1 eV

jan26

Suggest what would happen if an electron radiated energy when in orbit around a proton. (2)

The kinetic energy of the electron would decrease Or The potential energy would become more negative

The electron would spiral into the nucleus/proton Or The radius will decrease

A: A s^-1 V^-1

D: Because friction force = Fc

B:
because at X it is the furthest from both charges.

Electrons move through one plate to the other in the external circuit

When fully chargd, no electrons flow because both plates ae equally and oppositely charged. (and p.d)

Current decreases exponentially over time.

derive m/Q = 2V/v²
second question is in the image

ans for second qs is:
r= 4.7×10^-1 m

The electromagnet shown in the diagram provides a magnetic field which is used to deflect the ion along the tube of the spectrometer. Explain how a magnetic field can be used to deflect the ion into a circular path. (3)

the (magnetic) field acts at a right angle to the direction of motion Or
the velocity of the ion is perpendicular to the (magnetic) field

the force is perpendicular to the direction of motion.

the force acts as a centripetal force Or this is the condition for circular motion

A student suggests: “The ISS is travelling at a constant speed, so, according to Newton’s laws, there will be no resultant force acting on it.”

Criticise this suggestion