When a solid object is immersed in water, there is a loss in its weight. This loss is
An electric lamp of 100 watt is used for 10 hours per day. The ‘units’of energy consumed in one day by the lamp is
A stable nucleus (light with A < 10) has
Kilowatt-hour is the unit of
Which one among the following is used to make periscope?
Potential at a point due to a point charge is V. The charge is doubled and also the distance of the point from the charge is doubled. The new potential is