BlogPhysicsQCAA Multiple Choice Practice Questions for Unit 3 & 4 Physics External Assessment

# QCAA Multiple Choice Practice Questions for Unit 3 & 4 Physics External Assessment

Finding it difficult to practise for the multiple choice section of the QCAA Physics External (EA) without many practice questions? Well, we’ve come up with a bank of multiple choice questions so that you don’t have to keep doing the same past paper over and over.

These 25 practice questions also come with the answers, so you know if you’ve gotten questions right, or need to revise certain things.

Excited to start studying? Let’s get into the questions!

## Physics EA Multiple Choice Practice Questions

### Question 1

The definition of acceleration is the rate of change of

(a) Displacement

(b) Angle

(c) Velocity

(d) Momentum

### Question 2

What is the magnitude of the resultant vector?

(a) 20m

(b) 19m

(c) 21m

(d) 22m

### Question 3

What does the following Feynman diagram represent?

Image sourced from QCAA Physics Library

(a) Neutron Decay into Proton

(b) Bhabha scattering

(c) Electron repulsion

(d) Electron-Positron annihilation

### Question 4

A circular loop, which shrinks from a radius of 5cm to 3cm, is threaded by a magnetic field of strength 4mT. This process occurs over a time period of 5 seconds. Calculate the EMF.

(a) 5.56 * 10-6V

(b) 5.56 * 10-5V

(c) 7.28 * 10-6V

(d) 7.28 * 10-5V

### Question 5

What is the magnetic field strength of a solenoid with a current of 5A and 5000 turns?

(a) 4 * 10-2T

(b) 3 * 10-2T

(c) 2 * 10-2T

(d) 5 * 10-2T

### Question 6

A proton and and an electron are a distance of 10cm away from each other, what is the acceleration felt by the electron?

(a) 2.304 * 10-26ms-2

(b) 2.5 * 104ms-2

(c) 1.08ms-2

(d) 3.74 * 106ms-2

### Question 7

The definition of relativistic time is:

(a) The time measured from a newtonian frame of reference

(b) The time measured in the frame of reference of the moving object

(c) The time measured in the frame of reference of the stationary observer

(d) Time measured in any reference frame

### Question 8

A ball is projected at 4 different angles, 80°, 55°, 45° and 10°. Rank in  ascending order which angle will produce the largest horizontal displacement for the ball.

(a) 10° = 80°< 55° < 45°

(b) 45° < 55° < 80° = 10°

(c) 10° = 80°< 45° < 55°

(d) 10° > 45° > 55°> 80°

### Question 9

Two planets experience a gravitational force of F at a distance of r from one another. What distance do they need to be from each other to experience a force of  1/2F?

(a) 2r

(b) √(2r)

(c) 0.5r

(d) √(0.5r)

### Question 10

A particle undergoes uniform circular motion, the path it traces has a radius of 3cm and the particle takes 0.5s to do a full revolution. What is the particle’s acceleration towards the centre of the circle?

(a) 9.8ms-2

(b) 3.9ms-2

(c) 7.4ms-2

(d) 4.7ms-2

### Question 11

A 2m wire carrying a current of 3A is placed at some angle theta in a magnetic field of strength 6T. It experiences a force of 25N. What is the angle between the wire and the field to the nearest degree?

(a) 54°

(b) 44°

(c) 42°

(d) 49°

### Question 12

What is the angular momentum of an electron in the third energy level?

(a) 3.16 * 10-33

(b) 3.16 * 10-34

(c) 4.21 * 10-34

(d) 2.11 * 10-34

### Question 13

A plank of stationary length 3m is moved at a speed of 0.8c. To what length does the plank appear to a stationary observer?

(a) 5m

(b) 3m

(c) 1.5m

(d) 1.8m

### Question 14

If an object has 50J of potential energy initially with 30J of potential and 20J of kinetic energy after some timestep, what was the initial speed of the object?

(a) 0m/s

(b) 5m/s

(c) 2.5m/s

(d) 20m/s

### Question 15

How far does an object travel if 50Nm of work is done it with a constant force of 10N?

(a) 10m

(b) 50m

(c) 25m

(d) 5m

### Question 16

The definition of a gravitational field is:

(a) A region of space around an electrically charged object or object within which a force is exerted on other electrically charged objects

(b) An area where an acceleration of 9.8ms-2 is experienced

(c) A region of space around a mass within which a force is exerted on other objects with mass.

(d) An attractive force felt between two bodies with mass.

### Question 17

A ball is projected at an angle of 20° to the horizontal with an initial horizontal velocity of 25m/s. What is the ball’s initial velocity to the nearest 1 decimal place?

(a) 26.6m/s

(b) 25.7m/s

(c) 73.1m/s

(d) 71.3m/s

### Question 18

What is the magnitude and direction of the electric field produced by an electron at a distance of 5cm?

(a) 5.76 * 10-6, away from electron

(b) 5.76 * 10-7, away from electron

(c) 5.76 * 10-7, towards electron

(d) 5.76 * 10-6, towards electron

### Question 19

A particular step-up transformer is set up in such a way that the voltage is doubled. The primary voltage is 50V with 100 turns. How many turns are on the second coil?

(a) 125

(b) 85

(c) 200

(d) 150

### Question 20

A circular loop of radius 10cm experiences an EMF of 25V as the magnetic field it is in changes from 5T to 3T. How long does this process take to the nearest 5 seconds?

(a) 550s

(b) 400s

(c) 350s

(d) 425s

### Question 21

Which list contains only leptons?

(a) Gluon, electron, graviton, muon

(b) Muon, tau, positron, tau neutrino

(c) Electron, muon neutrino, tau neutrino, muon

(d) Tau neutrino, electron neutrino, Gluon, muon

### Question 22

What is the maximum wavelength that could possibly be emitted by a surface at a temperature of 473.15K as predicted by Wien?

(a) 6.1865nm

(b) 7.3015cm

(c) 7.4396km

(d) 6.1249m

### Question 23

What is the energy of a photon with momentum of 2.5 * 10-12kgms-1?

(a) 7.5 * 10-4J

(b) 7.5 * 10-7J

(c) 5.6 * 10-4J

(d) 5.6 * 10-4J

### Question 24

Which of the following is one of Newton’s laws?

(a) The change in an objects energy is equal to the change in its mass multiplied by the speed of light squared

(b) The net force experienced by an object is equal to the product of its mass and its acceleration

(c) All planets move around the sun in elliptical orbits, having the sun as one of their foci.

(d) The force of attraction between two point particles is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

### Question 25

What is the orbital radius of an asteroid that takes 3 days to orbit the earth?

(a) 60,000km

(b) 6.78 * 1042km

(c) 6.78 * 1045km

(d) 7.25 * 1042km

## On the hunt for other QCAA Physics resources?

We’ve got plenty more practice questions for you to use to revise previous content from throughout the year! Check them out:

The Best Place to Put Your Focus and Time into when Studying for the External Exams!

You’ll also want to have a look at our nifty guides for working on your QCAA Physics assessments below:

## Are you looking for some extra help with the QCAA Unit 3 & 4 Physics External Assessment?

#### We have an incredible team of QLD Physics tutors and mentors!

We can help you master the QCAA Physics syllabus and ace your upcoming Physics assessments with personalised lessons conducted one-on-one in your home or online!

We’ve supported over 8,000 students over the last 11 years, and on average our students score mark improvements of over 20%!

To find out more and get started with an inspirational QLD tutor and mentor, get in touch today or give us a ring on 1300 267 888!

​​William Bye is a Content Writer at Art of Smart and is currently studying a Bachelor of Advanced Science with Honours (majoring in Physics) at the University of Queensland. He was part of the very first cohort in Queensland to go through the ATAR system and wishes to help other students to make this journey as easy as possible. Will enjoys his time playing guitar in a band with his friends and hopes to continue balancing his science and music for many years to come.

## 45,861 students have a head start...

Get exclusive study content & advice from our team of experts delivered weekly to your inbox!