Sometimes Venus appears in the eastern sky before sunrise. Sometimes it appears in the western sky just after sunset. Therefore it is often called a morning or an evening star, although it is not a star.
Humidity is the amount of water vapour present in air. Absolute Humidity is the weight of actual amount of water vapour present in unit volume of air.Relative Humidity is the Ratio of water vapour in air at a particular temp. to total amount of water vapour required to saturate the same air at same temperature. It is expressed in %Specific Humidity is the Weight of water vapour present in per unit weight of air. It is not affected by change in pressure or temperature.
Ultrasound refers to a sound wave with a frequency greater than the upper limit of human hearing, which is generally over 20 kHz. In general, humans can hear sounds with a frequency between 20 Hz and 20 kHz.
EXAMIANS