Daily NEET MCQ- May 24, 2022 - NEET MCQ

Electromagnetic waves are formed by transverse motion of electric & magnetic fields. Thus, they are said to be transverse waves.

A way of looking at a travelling wave is considering the direction in which a particular value of transverse displacement moves. For the given equation x = Asin(ky+wt+a) we have to see the direction in which x moves. For eg: If we consider the amplitude A, for x =A as t increases, y should decrease. So, we can say that the wave propagates in the negative y direction.

In the given equation the phase is 3x-2t+π/2.
This is repeated after every 2π.
∴ sin( 3x-2t+π/2) +2nπ = sin( 3x-2t+π/2).
We can consider the case at t=0, sin(3x+π/2) = sin(3x+π/2+2nπ)
OR cos(3x) = cos(3x+2nπ)
∴ n = 1 for minimum difference.
Minimum distance can be found from kx = 2π
OR x = 2π/k = 2π/3.

Ethanal can be prepared by oxidation of ethene, in the presence of an ionic catalyst in an aqueous medium. This is a greener method and gives 90% of yield.

Tetrachloroethene was used as a solvent for dry cleaning purposes. It is a suspected carcinogen and groundwater contaminant. It is replaced by greener solvent like supercritical CO₂.

Synthetic methods should avoid using or generating substances toxic to humans and/or the environment. Hence less hazardous chemical synthesis is an important principle.

Hormone receptors are proteinaceous in nature. These receptors are located on or inside the cells. It is where a hormone binds on a cell. The binding of the hormone signals the cells to perform their tasks.

Receptors are the structures of the cell to which hormones bind and form hormone-receptor complex. They do not disintegrate. Receptors are specific for each hormone. Intracellular receptors are present in the cytoplasm.

Glucagon is a peptide hormone. It is synthesized and secreted by the alpha cells of the pancreas. The function of glucagon is to break glycogen into glucose. This raises the blood sugar level.

Hypothalamic hormones are peptides. They are secreted by the hypothalamus. Peptides, steroids, iodothyronines and amino acid derivatives are the different categories of hormones.