• 9702 June 2009 Paper 4 Worked Solution | A-Level Physics

Question 1 - See solution 29 at

A spherical planet has diameter 1.2 × 104 km. The gravitational field strength at the surface of the planet is 8.6 N kg–1.




Question 4 - See solution 30 at
A vertical peg is attached to the edge of a horizontal disc of radius r, as shown in Fig. 4.1.




Question 6 - See solution 289 at
A large horseshoe magnet produces a uniform magnetic field of flux density B between its poles. Outside the region of the poles, the flux density is zero.



Question 7 - See solution 23 at
You are provided with a coil of wire, a bar magnet and a sensitive ammeter. Outline an experiment to verify Lenz’s law.




Question 9 - See solution 22 at
(a) A sample of a radioactive isotope contains N nuclei at time t. At time (t + Δt), it contains (N – ΔN) nuclei of the isotope.




Question 10 - See solution 930 at
By reference to an amplifier, explain what is meant by negative feedback.



Question 11 - See solution 973 at
Explain the main principles behind the use of ultrasound to obtain diagnostic information about internal body structures.