Two strips of metal are riveted together at their ends by four rivets, each of diameter 6.0 mm. What is the maximum tension that can be exerted by the riveted strip if the shearing stress on the rivet is not to exceed `6.9 xx 10^7` Pa? Assume that each rivet is to carry one quarter of the load.

A copper wire of diameter 1.0 mm carries a current of 0.2 A. Copper has 8.4 xx 10^28 atoms per cubic metre. Find the drift velocity of electrons, assuming that one charge carrier of 1.6 xx 10^-19 C is associated with each atom of the metal.

Two narrow bores of diameters 3.0 mm and 6.0 mm are joined together to form a U-tube open at both ends. If the U-tube contains water, what is the difference in its levels in the two limbs of the tube ? Surface tension of water at the temperature of the experiment is 7.3xx 10^-2 N m^-1 '. Take the angle of contact to be zero and density of water to be 1.0xx 10^3 kg m^- 3 ( g = 9.8 m s^-2 ) .

A rheostat has 100 turns of a wire of radius 0.4 mm having resistivity 4.2 xx 10^-7Omega m. The diameter of each turn is 3 cm. What is the maximum value of resistance it can introduce?

An electric dipole consists of two opposite charges each of magnitude 6xx 10^-8 coulomb separated by 6.0 cm. The dipole is placed in an external electric field of 5xx10^-5NC^-1 What maximum torque will the field exert on the dipole?