A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).

Correct Option: C

A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).

Long distance means higher wastage of energy. So High-voltage direct-current (HVDC) technology is used for greater efficiency in very long distances. Electricity is transmitted at high voltages (110 kV or above) to reduce the energy lost in long-distance transmission.

Correct Option: B

Long distance means higher wastage of energy. So High-voltage direct-current (HVDC) technology is used for greater efficiency in very long distances. Electricity is transmitted at high voltages (110 kV or above) to reduce the energy lost in long-distance transmission.

If the poured liquid is relatively hotter or colder in comparison to the tumbler, it will break. When hot water is poured into a tumbler there is an uneven increase in the thermal expansion of the walls of the vessel. If the expansion is uneven enough and the strength of the glass is not strong enough, the tumbler breaks. However, if the poured water is colder in comparison to the tumbler, it breaks due to contraction and unequal temperature difference between the layers.

Correct Option: B

If the poured liquid is relatively hotter or colder in comparison to the tumbler, it will break. When hot water is poured into a tumbler there is an uneven increase in the thermal expansion of the walls of the vessel. If the expansion is uneven enough and the strength of the glass is not strong enough, the tumbler breaks. However, if the poured water is colder in comparison to the tumbler, it breaks due to contraction and unequal temperature difference between the layers.

Transformers have made long-distance transmission of electric power a practical reality, as AC voltage can be “stepped up” and current “stepped down” for reduced wire resistance power losses along power lines connecting generating stations with loads. At either end (both the generator and at the loads), voltage levels are reduced by transformers for safer operation and less expensive equipment.

Correct Option: B

Transformers have made long-distance transmission of electric power a practical reality, as AC voltage can be “stepped up” and current “stepped down” for reduced wire resistance power losses along power lines connecting generating stations with loads. At either end (both the generator and at the loads), voltage levels are reduced by transformers for safer operation and less expensive equipment.

n air cooler works on the simple principle of evaporation. It does not yield good results when humidity is high. On the contrary, the temperature of dry air can be dropped significantly through the phase transition of liquid water to water vapor (evaporation), which can cool air using much less energy than refrigeration.

Correct Option: B

n air cooler works on the simple principle of evaporation. It does not yield good results when humidity is high. On the contrary, the temperature of dry air can be dropped significantly through the phase transition of liquid water to water vapor (evaporation), which can cool air using much less energy than refrigeration.