## Wednesday, 17 September 2014

### ELECTROMAGNETISM

1. Derive the expression for magnetic field due to a straight current carrying conductor of finite length.
2. Derive the expression for magnetic field due to a current carrying circular coil.
3. Describe the construction and working and derive the expression for frequency in a cyclotron.
4. State Biot and Sarvart’s law.   Deduce the expression magnetic field produced at the centre of a circular loop.
5.  Describe the construction and working of a tangent galvanometer.
6.  Calculate the magnetic field at the centre of a tangent galvanometer coil of 50 turns and radius 10 cm when a current of 1A passes through it.     ( B x 10-4 T )
7. Calculate the magnetic field in which the cyclotron dees should be placed to acceralate protons.   The applied frequency is 8 MHz, mass of the proton = 1.67 x 10-27 Kg.      (    0.524 T)
8. Calculate the force per unit length on a long straight wire carrying current of 4 A due to a parallel wire carrying current of 6A.   The distance between the two wires is 3 cm.      (1.64 x 10-4 Nm-1)