How does one explain increase in resistivity of a metal with increase in temperature ?
Calculate the current drawn from the battery by the network of resistors shown in the figure.
What is the value of the angle between the vectors and for which the potential energy of an electric dipole of dipole moment , kept in an external electric field , has the maximum value.
Give an example of a material each for which temperature coefficient of resistivity is:
(i) positive, (ii) negative.
Graph showing the variation of current versus voltage for a material GaAs is shown in the figure, identify the region of :
Why must electrostatic field at the surface of a charged conductor be normal to the surface at every point ? Give reason.
Why are electric field lines perpendicular at a point on an equipotential surface of a conductor ?
Draw a graph to show the variation of resistance of a metal wire as a function of its diameter keeping its length and material constant.