Thick lens will have shorter and consequently thin lens will have greater focal length. Because, For a thick lens, the optical path length of the light is more, than for a thin lens, thus, the bending of light will be more in case of a thicker lens. Consequently, it has a shorter focal length.
Answer:
1. heat engine ~~ •a machine that converts the internal energy of a fuel into mechanical energy.
2. heat pump ~~ •an appliance that extracts heat energy from one source and deposits it
elsewhere.
3. Boiler ~~ •a heating appliance that uses heat energy released from fossil fuels to warm water for use in radiant or
convection heating systems.
4. Thermostat ~~ •an appliance that controls the maintenance temperature of a heating
system
