Questions

Processes that require or give off heat will be limited to changes of state, known as phase changes, and changes in chemical constitution, or chemical reactions. Changes of state involve a solid melting, a liquid freezing, a liquid boiling or a gas condensing.

An exothermic process is one that gives off heat, which is transferred to the surroundings. An endothermic process is a reaction which heat has to be supplied to the system from the surroundings.

Here in all the given options, heat is taken away from them to change there phase. 

Liquid to Solid --- Freezing

Gas to Liquid --- Condensation

Gas to Solid --- Deposition 

are all examples of exothermic processes.

Conditions suitable for the formation of a tornado develop when varying temperatures and humidity come together and form thunderclouds. This refers to the presence of warm and moist condition in the lower atmosphere and cold and dry conditions in the upper atmosphere. The place where these varying masses of air meet is known as the dry-line. Such conditions, which are suitable for the formation of a tornado, are most often observed just before a low pressure system develops.

Once the ideal conditions occur, the warm air tries to rise in the atmosphere, while the cold air blocks it. This makes the air in between rotate horizontally. In the meanwhile, the land is heated by the Sun, and hence, the air near the ground becomes warm and starts rising. Continuous fueling by the heat energy from the Sun ensures that the warm air has an upper hand over cold air. As a result of this, the cold air at the top starts sinking and the warm air below starts rising in a spinning motion. As the amount of warm air increases, the formation gains height and becomes intense. The intensity of these devastating tornadoes is such that they can clear off anything that comes in their path.

The world's fastest elevator that can operate at a record speed of 1,260 meters per minute is set to be installed in a skyscraper complex in China. The elevator has various safety features including brake equipment that uses materials with high heat resistance. Apart from this, the elevator can absorb vibration during the high-speed operation to make the ride comfortable.

Uttar Pradesh is the Indian state which share the most borders with 9 different states.

Neighbouring States of Uttar Pradesh –

Uttarakhand and Himachal Pradesh in northwest,

Delhi, Haryana and Rajasthan in west,

Madhya Pradesh in south,

Chhattisgarh in southeast,

Bihar and Jharkhand in east.