GATE Questions

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Stamps are what travel around the worldstaying in one spot. Slippers and walking stick can also travel around the world but they will not stay at one spot. So they are eliminated.

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.

This orbital velocity at the moon is less because orbital velocity = rg

where 'r ' is the orbital radius. i.e the distance of the body from the center of the earth and 'g' is the acceleration due to gravity on the body in question. In the case of the moon, both r and g are less than in the case of the earth.

The Qatar Airways has launched the World’s longest scheduled commercial service to ply between Doha to Auckland. The inaugural service of Flight QR920 took off on February 5, 2017 from Doha and will take 16 hours and 20 minutes to travel 14,535 kilometers to reach Auckland in New Zealand.
This makes Qatar Airways to launch the World’s fastest and longest passenger service in terms of flying time. Prior to this, emirates launched the world’s longest non-stop scheduled commercial flight with a service from Dubai to Auckland, spanning 14,200 kilometres.

The usual cause of sea breeze is the difference in specific heat capacity between land and water Land heats and cools more quickly than water.

What is the cause of a sea breeze?

The air over the land is warmed and rises, to a greater temperature than that over the sea. This produces a convection current, with cooler air flowing in from over the sea to replace that rising from the land. At night the land cools more than the sea, so the action reverses to produce a land-breeze, blowing off the land.

Amino acids are organic compounds containing amine (-NH2) and carboxyl (-COOH) functional groups, along with a side chain (R group) specific to each amino acid.

Depending on the nature of the side chain groups, three classes of aminoacids can e distinguished:

1. Amino acids with H ond donor and acceptor groups.

Histidine, lysine, aspartic acid, threonine,...

2. Amino acids with donor grups only.

Arginine, tryptophan and cysteine.

3. Amino acids with acceptor groups only.

Asparagine and glutamine.

A substance that cannot be decomposed (broken down) into simpler substances by ordinary chemical means.

Examples: gold, iron, carbon, hydrogen, oxygen, nitrogen.

Material composed of only one kind of matter throughout (same atoms or same molecules).

Covalent bonds hold atoms together because the attraction between the positively charged nuclei and the negatively charged shared electrons is greater than the repulsions between the nuclei themselves.