The current produced by upwelling of cold water off the coast of Chile and Peru is known as

A one-rupee coin is placed at the bottom of a vessel. Water is then poured into the vessel such that the depth of water becomes 20 cm. If water has refractive index 4/3, the coin would be seen at a depth of

The spread in colours in a rainbow on sky is primarily due to

Gravitational force shares a common feature with electromagnetic force. In both cases, the force is

A current I flows through a potential difference V in an electrical circuit containing a resistance R. The product of V and I i.e. VI may be understood as

An optician prescribes a power = - 0.5 dioptre. The corresponding lens must be a