Physics Questions

A device which is used to convert light energy directly into electrical energy is called as photovoltaic cell or a solar cell.

Heliostats convert light energy into heat energy.

A thermocouple is a device for measuring temperature.

Parabola, because when the coin is dropped at a particular point, it has the same velocity as the running train. So by Newton's first law, it continues its motion horizontally with that velocity. But then, it is also pulled down by earth's gravity continuously. In this situation its horizontal motion gives way to the parabolic motion until it reaches the ground.

Cohesion refers to attraction between molecules of the same kind while adhesion refers to attraction between different kinds of molecules

Hydroelectricity is electricity produced from hydropower i.e, water.

Heat transfer through radiation takes place in form of electromagnetic waves mainly in the infrared region. It depends on nature of the body, its temperature and kind & extent of its surface.

This acceleeration denoted by letter g varies from place to place. Unless stated otherwise, it can be taken 9.8 m/s2.