Daily NEET MCQ- June 17, 2022 - NEET MCQ

As the air is moving, we can solve this question from the air’s frame of reference. From the air’s frame of reference, the observer will be going towards the observer at 2m/s and the source will be coming towards the observer at 10-2 = 8m/s.
F = f(v+v₀)/(v+v₈)
= 20(330+2)/(330-8)
= 20*332/322 = 20.62Hz.

Speed of sound in the medium depends on the properties of the medium like bulk modulus and density, not on the speed of source creating the sound.

Apparent frequency F = f(330+v₀)/(330+v₈)
= 10(330)/(330-10) = 10.31Hz.
Wavelength = 330/F
= 330/10.31
= 32.007m = 32m.

Apparent frequency only depends on velocity and not the distance between source and observer. So, maximum frequency will be heard when speed is maximum, which is at the start. F = 50(330)/(330-20)
= 53.22Hz.

Beryllium, differs from the rest of the members of its group due to the following reasons: beryllium has a small atomic and ionic size, it has no vacant d-orbitals and it has a higher charge density comparatively.

Beryllium oxide (BeO) and beryllium hydroxide [Be(OH)₂] are amphoteric in character they also dissolve in acid to form a salt and beryllate in alkali. Beryllate is any salt containing an anion BeO₂^2-.

The atria are the two upper chambers of the heart. The walls of the atria secrete a hormone known as atrial natriuretic factor or ANF. Its function is to reduce blood pressure to maintain homeostasis.

ANS or atrial natriuretic factor is secreted by the walls of the atria of the heart. Its effect is to dilate the blood vessels. As a result, blood is provided more space to flow, and hence the blood pressure decreases.

Atrial natriuretic factor or ANF is secreted by the walls of the atria of the heart. Its effect is to dilate blood vessels and hence decrease blood pressure. Adrenaline and noradrenaline increase blood pressure.

The kidney produces erythropoietin. It is produced by the juxtaglomerular cells of the kidney. Angiotensinogen and thrombopoietin are produced by the liver. Somatostatin is secreted by the pancreas.