Answer: D) Near distance Explanation: Stars twinkle because they’re so far away from Earth that when light from the stars passes through the atmosphere, it is bent countless times due to refraction, making it look like as if they were blinking. The sun and other planets doesn’t twinkle because it’s too close to Earth compared to other stars.

A solution is a homogeneous type of mixture of two or more substances. A solution has two parts:: 1. A solute and 2. A solvent.   The solute is the substance that dissolves, and the solvent is the majority of the solution.

Answer: D) Panacea Explanation: Panacea, also known as panchrest, is a medicine supposed remedy that is claimed to cure all diseases and prolong life indefinitely. It is named after the Greek goddess of universal remedy Panakeia.

Answer: B) Urochrome Explanation: The yellow color of urine is due to the presence of a yellow pigment, urochrome. The color of normal urine is usually light yellow to amber. Generally the greater the solute volume the deeper the color.

Answer: C) Vacuum Explanation: Sound waves cannot travel through a Vacuum.   A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibrations to work in.

Answer: A) Ribosomes Explanation: Ribosomes are present in prokaryotic cells. These are organelles which consist of two subunits. They are present in both Eukaryotic and Prokaryotic cells. They are made up of RNA and proteins and present in the cytoplasm and on the membranes and are involved in protein synthesis.

Answer: C) Wasshing soda Explanation: Hardness can be removed by adding sodium carbonate (washing soda) or by passing the water through an ion-exchange column.   Hardness in water is caused by dissolved magnesium ions and calcium ions. These can get into the water when it comes into contact with limestone and other rocks that contain calcium compounds. This can happen, for example, when rainwater flows over these rocks on its way to a reservoir.   Hardness in water is of two types. They are : 1. Temporary hardness 2. Permanent hardness   1. Temporary hardness:: Temporary hardness is caused by dissolved calcium hydrogen carbonate. 2. Permanent hardness:: Permanent hardness is caused by dissolved calcium sulfate. Unlike temporary hardness, it is not removed by boiling the water.

Answer: A) 20 Explanation: 6 choose 3 means number of possible unordered combinations when 3 items are selected from 6 available items i.e, nothing but 6C3. Now 6C3 = 6 x 5 x 4/3 x 2 x 1 = 120/6 = 20.