A circular loop of radius 0.3 cm lies parallel to a much bigger circular loop of radius 20 cm. The centre of the small loop is on the axis of the bigger loop. The distance between their centres is 15 cm. If a current of 2.0 A flows through the smaller loop, then the flux linked with bigger loop is:

(1) 9.1 x 10^{-11} weber (2) 6 x 10^{-11} weber (3) 3.3 x 10^{-11} weber (4) 6.6 x 10^{-9} weber

A projectile is given an initial velocity of , where is along the ground and is along the vertical. If g = 10 m/s^{2}, the equation of its trajectory is:

Diameter of a plano – convex lens is 6 cm and thickness at the centre is 3 mm. If speed of light in material of lens is m/s, the focal length of the lens is: