The thickness at the centre of a plane convex lens is 3 mm and the diameter is 6 cm. If the speed of light in the material of the lens is 2 $$\times$$ 10⁸ ms^$$-$$1. The focal length of the lens is ____________.

For what value of displacement the kinetic energy and potential energy of a simple harmonic oscillation become equal ?

An AC current is given by I = I₁ sin$$\omega$$t + I₂ cos$$\omega$$t. A hot wire ammeter will give a reading :

A modern grand - prix racing car of mass m is travelling on a flat track in a circular arc of radius R with a speed v. If the coefficient of static friction between the tyres and the track is $$\mu$$_s, then the magnitude of negative lift F_L acting downwards on the car is : (Assume forces on the four tyres are identical and g = acceleration due to gravity)