# Trial Physics Revision 2017

In most schools in NSW the trial HSC examinations occur in three weeks. Class assessment tasks have finished so we can now concentrate on studying. How can you best prepare for these examinations? First, you must have a study timetable, just like a daily school timetable where you have 60 minutes for each subject. Stick to the schedule. Have a 10 minute break between study sessions. Secondly, in your study sessions work through past examination questions by writing down answers on lined paper. Set out your work in an organised fashion so that this habit becomes automatic in examinations. Remember that perfect practice makes perfect. Here are some Physics revision questions:

1. Reliability An experiment is performed to measure the acceleration due to gravity. Outline how we can make the result reliable.
2. Ceramic Insulators Outline the function of the ceramic insulators on electricity transmission lines.
3. Silicon and Germanium Describe the advantages of silicon over germanium in semiconductor devices.
4. Zeeman Effect Describe the Zeeman effect. How is it explained?
5. Orbital Speed The orbital speed of a satellite moving in a circular path of radius r is v. Find the orbital speed of a satellite moving about the same planet in a circle of radius 2r.
6. DC Motor A simple DC motor has one rectangular coil of wire placed in a uniform magnetic field. Explain, using a diagram, why the magnetic force on each side of the coil is constant as it spins but the torque acting on the coil is not.
7. Superconductors Superconducting magnets are used to produce very strong magnetic fields in particle accelerators. Explain how this is possible if the magnetic field inside a superconductor is zero.
8. Matter Waves A student states that an electron is described as a particle moving along a standing wave. Explain why this is incorrect.
9. Relativity A spacecraft travels at a constant velocity v between two planets that are a distance d apart. Determine the time taken for the journey according to (a) the reference frame of the planets (b) the reference frame of the spacecraft.
10. Split-Ring Commutator A split-ring commutator is connected to the output terminals of a single coil generator that is spinning at a constant rate. Draw graphs showing for one rotation of the coil (i) the current in a particular side of the coil (ii) the magnetic force on this side of the coil (iii) the current in a particular brush (iv) the electrical power in the coil (v) the mechanical power suplied to the coil
11. Resistance A copper wire is maintainted at a temperature of 2K. Describe how an electric current flows through the conductor.
12. Uncertainty Principle An observation is made of the position of an electron. How does this affect the momentum of the electron?
13. Rocket Motion A rocket starts from rest and accelerates vertically upwards due to the expulsion of exhaust gases at a constant speed relative to the rocket. The mass of the rocket decreases at a constant rate. Draw graphs showing for the same time interval the rockets (i) acceleration (ii) velocity (iii) distance travelled (iv) momentum.
14. AC An alternating current of peak value I flows in a conductor of resistance R. Show that the heat energy released during one cycle of the AC is one-half of that of a constant current I.
15. Cathode Rays A glass tube contains air. A high voltage is applied between two electrodes in the tube. Describe the appearance of the discharge in the tube as the pressure in the tube is reduced.
Comment