Two wires of equal length, one of copper and the other of manganin have the same resistance. Which wire is thicker?

What are the directions of electric and magnetic field vectors relative to each other and relative to the direction of propagation of electromagnetic waves?     

A bar magnet is moved in the direction indicated by the arrow between two coils PQ and CD.

Mention the two characteristic properties of the material suitable for making core of a transformer. 

A charge ‘q’ is placed at the centre of a cube of side l. What is the electric flux passing through each face of the cube? 

A test charge ‘q’ is moved without acceleration from A to C along the path from A to B and then from B to C in electric field E as shown in the figure. (i) Calculate the potential difference between A and C. (ii) At which point (of the two) is the electric potential more and why? 

An electric dipole is held in a uniform electric field.

(i) Show that the net force acting on it is zero.

(ii) The dipole is aligned parallel to the field. Find the work done in rotating it through the angle of 180°.

State the underlying principle of a transformer. How is the large scale transmission of electric energy over long distances done with the use of transformers?  

A capacitor of capacitance of ‘C’ is being charged by connecting it across a dc source along with an ammeter. Will the ammeter show a momentary deflection during the process of charging? If so, how would you explain this momentary deflection and the resulting continuity of current in the circuit? Write the expression for the current inside the capacitor.

10.

A light bulb is rated 100 W for 220 V ac supply of 50 Hz. Calculate

(a) the resistance of the bulb;

(b) the rms current through the bulb

 

OR

 

An alternating voltage given by V = 140 sin 314 t is connected across a pure resistor of 50 W. Find

(i) the frequency of the source.

(ii) the rms current through the resistor.