Answer: B) Both sequentially and parallelly Explanation:

Answer: A) i Explanation: We know that, i2 = -1i3 = i2 x i = -1 x i = -ii4 = i2 x i2 = -1 x -1 = 1Hence, i233  =i4 x 58 + 1 = i232 x i1 = 1 x i = i

Answer: D) All the above Explanation: Viruses are responsible for some of the most dangerous and deadly diseases including influenza, ebola, rabies and smallpox. Despite their potential to kill, these potent pathogens are in fact considered to be non-living.   Reasons: 1. Viruses don't have any cells, like living organisms do. They have protein coats but no organelles or other cellular machinery. Just a little DNA packet. 2. Viruses can't produce new proteins, DNA, or RNA and therefore are unable to reproduce on their own. They need infected cells' machinery to make all of these and produce new virons. 3. Viruses have no metabolic activity. They don't use or convert energy and have no ongoing interior processes. They're basically just inert structures until they impact a potential host cell.

Answer: A) Chemical Explanation: In rusting the Iron ore make a chemical reaction with the oxygen in the presence of water and environmental or atmospheric moisture to produce an Iron oxide. Iron oxide is otherwise called as rust. The rusting of iron is a chemical change because it is two substances reacting together to make a new substance.

Answer: A) Fourth generation Explanation: Microprocessors are used in the computers of fourth generation computers. Personal microcomputers were possible due to the microprocessors.   Microprocessors further revolutionized the development of computers.   The first microprocessor called Intel 4004 was developed by American Intel Corporation in 1971.

An Umbrella. Yes, when it is open it can't be fit under a chimney but when it is closed it can be fit down a chimney.

Answer: C) Backup file Explanation: In computing, ".bak" is a filename extension commonly used to signify a backup copy of a file.

Answer: A) Retinol Explanation: Vitamin A is a group of unsaturated nutritional organic compounds that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids. IUPAC Name :: (2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohexen-1-yl)nona-2,4,6,8-tetraen-1-ol   Vitamin Name - Chemical Name Vitamin A   -     Retinol Vitamin B1  -    Thiamine Vitamin B2  -    Riboflavin Vitamin B3  -    Niacin Vitamin B5  -    Pantothenic acid Vitamin B6  -    Pyridoxin Vitamin B7  -    Biotin Vitamin B9  -    Folic acid Vitamin B12  -   Cyanocobalamin Vitamin C     -   Ascorbic acid Vitamin D     -   Calciferol Vitamin E      -   Tocoferol Vitamin K      -   Phylloquinone and Menaquinones