Write the equation connecting resistivity of the material with relaxation time.

Write the equation connecting torque with force.

Write the relation connecting voltage and time

In all metallic conductors, electric conduction is due to drifting of free electrons. But the resistivity of different metals are different. Arrive at an expression for electrical resistivity a metal in terms of relaxation time.

Write the relation between resistivity and average collision time for electron.

Magnification is the ratio of the height of the image to the height of the object. Write the equation of a concave mirror connecting the distance of the image and distance of the object.

Static friction opposes impending motion. Write the mathematical equation connecting the limiting value of static friction with normal reaction.