Daily NEET MCQ- June 7, 2022 - NEET MCQ

Volume of drop = 4/3πR².
Let the radius of droplets be ‘r’. Volume of big drop will be equal to volume of 10 droplets.
10*4/3πr³ = 4/3πR³ ⇒ r = 10^1/3 *R.
Surface area of big drop = 4πR² & surface area of 10 droplets = 10 * 4πr² = 40πR²(10^2/3).
Surface energy of big drop = 4πR² *S = 4π(0.0025)*0.08 = 0.0025
Surface energy of droplets = 40πR²(10^2/3) *S = 40π(0.0025)(10^2/3)*0.08 = 0.1166.
Change in surface energy = 0.1166 – 0.0025 = 0.1141 J.

The diametrical cross section of a sphere will be a circle of radius R. One hemisphere will exert a force of Sdl (dl is a small element of length along periphery) on dl length.
Total length = perimeter of circle = 2&7pi;R. Therefore, total force = 2πRS.

Let the pressure outside the bubble be P₁, between the two layers be P₂ and pressure inside the bubble be P₃.
P₂ – P₁ = 2S/R
P₃ – P₂ = 2S/R
∴ P₃ – P₁ = 4S/R
This shows that excess pressure just inside the first layer is 2S/R while excess pressure completely inside the bubble is 4S/R.

Thermal energy is the result of the motion of a body’s atoms and molecules. It depends on the temperature and is directly proportional to each other. It’s the average of kinetic energy and is responsible for a body’s motion.

As we know that, the thermal energy is dependent on temperature, among the options milk at given temperature has a higher temperature, so milk posses higher thermal energy than others (temperature is proportional to thermal energy).

Thermal energy is also known as heat energy, it’s source s are the same as heat energy. As we know that micro-oven produces heat waves to raise food’s temperature and bake them, sun for solar energy and heater produces heat. Moon doesn’t.

Based on the number of axons and dendrites, the neurons are divided into three major types:
i. Multipolar neurons-with one axon and two or more dendrites
ii. Bipolar-with one axon and one Dendrite
iii. Unipolar-cell body with one axon only.

The myelinated nerve fibres are enveloped with Schwann cells, which form a myelin sheath around the axon. The gaps between the two adjacent myelin sheaths are called Nodes of Ranvier.

Myelinated nerve fibres are found in spinal and cranial nerves. Unmyelinated nerve fibres are enclosed by a Schwann cell that does not form a myelin sheath around the axon and is commonly found in autonomous and the somatic neural system.

A nerve impulse is transmitted from one neuron to another through junctions called synapses. A synapse is formed by the membranes of pre-synaptic and a post-synaptic neuron.