Question Discussion & Solution

The correct answer is Ethanol + Methanol​.

• Ethanol + Methanol​ is denatured alcohol.
• Denatured alcohol is ethanol that has additives to make it poisonous, bad-tasting, foul-smelling, or nauseating to discourage its recreational consumption.
• The term denatured alcohol refers to alcohol products adulterated with toxic and/or bad tasting additives (e.g., methanol, benzene, pyridine, castor oil, gasoline, isopropyl alcohol, and acetone), making it unsuitable for human consumption.
• The most common additive used is methanol (5–10%), giving rise to the term methylated spirits. Denatured alcohol is used as a lower-cost solvent or fuel for home-scale or industrial use.

Key Points

• Denatured alcohol is ethanol or grain alcohol that contains additional chemicals called denaturants that make it unfit for human consumption.
• Denatured alcohol is fine for some types of lab work and as an ingredient in certain products, but it's not safe to drink.
• Ethanol is an organic chemical compound. It is simple alcohol with the chemical formula C₂H₆O.
• Its formula can be also written as CH₃−CH₂−OH or C₂H₅OH and is often abbreviated as EtOH.

Additional Information

• Alcohol (ethanol or ethyl alcohol) is the ingredient found in beer, wine, and spirits that causes drunkenness.
• Alcohol is formed when yeast ferments (breaks down without oxygen) the sugars in different food. 

Explanation:

• The purpose of regression testing is to confirm that a recent program or code change has not adversely affected existing features.
• Regression testing is nothing but a full or partial selection of already executed test cases that are re-executed to ensure existing functionalities work fine.
• This testing is done to make sure that new code changes should not have side effects on the existing functionalities. It ensures that the old code still works once the new code changes are done.

The purpose of regression testing is to select test cases partially or fully to ensure existing functionalities work fine. Thus, regression testing is primarily related to functional testing

Need of Regression Testing

• Regression Testing is required when there is a change in requirements and code is modified according to the requirement or when one of the following has been done.
  • New feature is added to the software
  • Defect fixing
  • Performance issue fix

The correct answer is Mirage.

• To a distant observer, the light appears to be coming from somewhere below the ground.
• The observer naturally assumes that light is being reflected from the ground, say, by a pool of water near the tall object.
• Such inverted images of distant tall objects cause an optical illusion to the observer.
• This phenomenon is called a mirage.
•  The optical illusion which occurs mainly in the desert during hot summer is based on the principle of TIR i.e total internal reflection.
• This type of mirage is especially common in hot deserts.

Additional Information

• Total Internal Reflection (TIR): When a ray of light goes from denser to the rarer medium it bends away from the normal and as the angle of incidence in denser medium increases, the angle of refraction in the rarer medium also increases and at a certain angle, angle of refraction becomes 90°, this angle of incidence is called critical angle (C).
• When the Angle of incidence exceeds the critical angle then the light ray comes back into the same medium after reflection from the interface. This phenomenon is called Total internal reflection (TIR).
• Conditions for TIR: 
  1. The ray must travel from denser medium to rarer medium.
  2. The angle of incidence 'i' must be greater than the critical angle C.

The Correct Answer is Magnetic Force.

• Magnetic resonance imaging ( MRI) is one of the most popular medical imaging methods used in the world at many diagnostic centers.
• These MRI scanners use strong magnetic fields, gradients of the magnetic field, and radio waves to produce images of the organs inside the body.
• The magnetic force is a component of the electromagnetic force, one of nature's four basic forces, which is induced by charge movement.
• There would be a magnetic force of attraction between two objects containing charge in the same direction of motion, while objects in charge traveling in opposite directions have between them a repulsive force.

The correct answer is Spinning.

• The process of making thread from the fibre is called Spinning.

Key Points

• Spinning is the process done as a major part of the textile industries.
  • It is the manufacturing process for creating polymer fibres.
  • In the Spinning process, fibres are drawn and twisted from the cotton mass which brings them together to form a yarn
• Ring, Rotor, Air Jet are the different types of spinners used in the textile industries.

Additional Information

• Weaving is a method of textile production in which two different sets of yarns or threads are interlaced at right angles to form a fabric or cloth.
• Ginning is the process of removing the seeds and debris from cotton.