**1.** To indicate that the field is stronger at the certain place, draw the field lines closer.

- Note that for uniform electric fields, draw the field lines equally spaced, as the field strength is constant between the two plates.

**2.** Gravitational field/force questions.

- These ones usually involve finding the force between two objects (note: Newton’s third law indicates that the gravitational force acting on both objects will be the same), and the acceleration/ gravitational field strength on the surface of some planet (make sure you now all the units! There was a question like this on the exam this year). Furthermore, you can also be asked to find the radius or period of some object in orbit, and its best to use Kepler’s law for this (put it on your reference sheet).

- Make sure you also know all the properties of a geostationary satellite (ie. periodL24 hours, orbits over the equator of the planet etc.) VCAA Physics 2016 Question 6

- Understand the difference between apparent weight (W = N), weight, apparent weightlessness (Normal force = 0 N) and weightlessness (g = 0 Nkg^-1) ie. VCAA Physics 2013 Question 7c. You can also be asked to calculate the apparent weight of some object ie. VCAA Physics 2009 Exam 1 Question 7

- Make sure you also know how to calculate the work down from a gravitational field strength vs. distance graph, and gravitational field strength per kilogram vs. distance graph.

**3.** Electrical fields- Students usually find this one easier than gravitational fields

- So, it basically involves calculating the electric field strength between two plates that form uniform electric fields (using E = V/d).

**4.** Magnetic fields

- Understand how to use the right-hand rule, the right-hand slap rule and the right-hand slap rule for solenoids! (Note that the thumb only points in the direction of conventional current, so if the electron is moving towards the right, your thumb would point towards the left).

- Make sure that you know how to calculate force on moving particles, and current carrying wires using F = qvB and F = NILB respectively.

- The consequences of changing mass, velocity, magnetic field strength or charge on the radius of a moving charge moving through a magnetic field perpendicular to its motion (r= mv/qB).

- Regarding the DC Motor, you should also know that it converts electrical energy to mechanical energy and how a split ring commutator works (it reverses the current every half turn when the coil is at a right angle to the magnetic field). To increase the force/ torque, you can either have more loops, increase the current, have a stronger magnetic field or increase the battery voltage). There are lots of questions on DC Motor out there, so it shouldn’t be that hard to find one on this (Also note that you don’t have to know about AC motors at all from this year).