Electricity and Magnetism
Assignment # 2 Due Date: 15 November 2013
1. a) Write brief notes on the Hall effect. Show on a diagram the polarity of the Hall Voltage, together with a given current and magnetic field direction, assuming the charge carriers to be conduction electrons. [5]
b) Define electric dipole and the electric dipole moment. Write down an expression, in vector form, and show graphically the electric field intensity at point P on the normal to the axis of the dipole. [5]
2. a) What is the potential difference between points a and d in the circuit shown below.
[5]
(b)Find the terminal voltage of each battery. [5]
3. a) A uniform magnetic field (into the page) has a constant magnitude B = 0.200 T to the right of the dashed line and zero to its left. The distance d = 14.0 cm.
(i) Suppose the loop is held fixed in place and the voltage across the capacitor is initially 50.0 V. If the switch is closed at time t = 0, Determine the time tA for the current to fall to 3.0 x 10-3 A. [3]
(ii) What is the force on the loop at t = tA if the current flows in a clockwise direction? [3]
(b) After the capacitor has completely discharged, a force is applied to pull the loop to the left, out of the magnetic field, at a constant velocity v = 0.700 m/s.
(i) Calculate the magnitude of the induced . [3]
(ii) This will cause a current to flow which will charge the capacitor. Indicate which capacitor plate will become positively charged and give your reasoning. [3]
(c) (i) Using Ampere’s Law or otherwise derive an expression for the magnetic field B at the centre of an infinitely long solenoid of N turns, each carrying current i. Draw a diagram to show the direction of the field. [4]
(ii) Show that the self-inductance of such a solenoid depends only on geometrical parameters and given by: