General Science Questions (MCQs) for Competitive Examinations

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Chlorargyrite is the mineral form of silver chloride (AgCl). It is also known as cerargyrite and, when weathered by desert air, as horn silver. Silver chloride is formed by the disappearance of the initial silver oxide layer.

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Because of the screening effect, the net positive charge experienced by the electron from the nucleus is lowered and is known as effective nuclear charge. Effective nuclear charge experienced by the orbital decreases with increase of azimuthal quantum number(l).

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Radioactive materials are first encased in resin or concrete and sealed in steel drums. The drums are then packed into concrete casks and placed in concrete trenches up to 18 metres deep.

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The brain’s limbic system controls emotional expression through the hypothalamus, which has control over the body’s emotional responses systems. The hypothalamus is responsible for regulating hunger, thirst, response to pain, levels of pleasure, sexual satisfaction, anger and aggressive behavior, etc. It also regulates pulse, blood pressure, breathing, and arousal in response to emotional circumstances.

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Plant wilting occurs after excessive loss of water by transpiration and lesser absorption. i.e. rate of transpiration exceeds rate of water absorption. On a hot day, plants transpire heavily and cannot absorb water speedily to keep pace with transpiration loss, even when there is enough water.

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The central nervous system (CNS) controls most functions of the body and mind. It consists of two parts: the brain and the spinal cord. Both the brain and spinal cord are protected by a three-layered covering of connective tissuecalled the meninges.

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Skeletal muscle is a form of striated muscle which is under the voluntary control of the somatic nervous system. Most skeletal muscles are attached to bones by bundles of collagen fibres known as tendons. It is one of three major muscle types, the others being cardiac muscle and smooth muscle.

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Protein electrophoresis and Western blotting are both methods used to identify specific proteins in a sample or solution. Western blotting, also known as immunoblotting or protein blotting, is a core technique in cell and molecular biology. It is used to detect the presence of a specific protein in a complex mixture extracted from cells.

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The wings are modified forelimbs of birds which are the key to bird flight. Each wing is composed of three limb bones, the humerus, ulna and radius. Wings are much bigger than our arms, but being made mostly of feathers and hollow bones makes them very light. Their shape uses the wind to make flying easier.

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Acidity and alkalinity are expressed on the pH scale, which ranges from 0 (strongly acidic) to 14 (strongly basic or alkaline). A pH of 7.0, in the middle of this scale, is neutral. Blood is normally slightly basic, with a normal pH range of 7.35 to 7.45.