Practice Test - NEET MCQ

We can use a capacitor of suitable capacitance as a choke coil because the average power consumed per cycle in an ideal capacitor is zero. Therefore, like a choke coil, a condenser can reduce AC without power dissipation.

The opposition offered by a capacitor for the flow of A.C is called capacitive reactance.
Xc = 1/wC
it's SI unit is ohm

Natural Frequency of an LC Oscillator

- The natural frequency of an LC oscillator is determined by the values of the inductance (L) and capacitance (C) in the circuit.

- The LC oscillator is a type of oscillator circuit that uses a combination of inductors and capacitors to generate oscillations at a specific frequency.

- The natural frequency of an LC oscillator can be calculated using the formula:

f = 1 / (2 * π * √(LC))
 

Given, i₁​=i₂​=i
∴F=μ_0​i²l​/2πb
Hence, force per unit length is F=μ₀​i²​/2πb

The permeability of free space, μ0, is numerically equal to 4π x 10-7. For air and other non-magnetic materials, the absolute permeability is the same constant. For magnetic materials, absolute permeability is not a fixed constant but varies non-linearly with the flux density.

Tert-butyl chloride forms most stable 3° carbocation. So will give white precipitate of AgCl with AgNO₃ solution immediately.

Hence, option (B) is the answer.

During racemisation, carbocation intermediate is formed.

Hence option (A) is the answer.

Reactivity in S_N2 is inversely proportional to steric hindrance.

Hence the correct order of reactivity is CH₃Cl > CH₃CH₂Cl > (CH₃)₂CHCl > (CH₃)₃CCl

Hence, Option (c) is the answer.

In order to obtain ethoxy ethane from ethanol, the ethanol must be subjected to the effect of concentrated sulphuric acid at 413 Kelvin or 140°C as shown below:

Reaction involves rearrangement of carbocation

It is an oxo process of synthesis of alcohols.

Endocrine glands are ductless glands of the endocrine system that secrete their products, hormones directly into the blood. The major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus and adrenal glands.

The pituitary gland is a tiny organ, the size of a pea, found at the base of the brain. As the “master gland” of the body, it produces many hormones that travel throughout the body, directing certain processes or stimulating other glands to produce other hormones.

ANF (atrial natriuretic factor) is secreted by the atrial walls of the heart. It is responsible for a decrease in blood pressure. When the blood pressure is increased, ANF which is secreted dilates the blood vessels causing a decrease in blood pressure.

Thomas Addison was the first person who showed the relation between the secretion of the adrenal gland and Addison’s disease named after him.

The triploblastic animals have three prominent germ layers known as ectoderm, endoderm and mesoderm. Thymus gland develops from two hollow elongations (third and fourth pharyngeal pouches) of endoderm which descends to the embryonic thorax by the end of eight weeks of gestation. The lymphoid cells of the gland originate from mesoderm. Thus, the correct answer is option B.

Addison's disease is caused due to hyposecretion of steroid hormones from adrenal glands. The steroid hormones are cortisol and aldosterone which are secreted from adrenal cortex.
Cretinism is the retarded mental and physical development due to hyposecretion of thyroid hormones.
Dwarfism is the retarded physical development due to hyposecretion of growth hormone during period of skeletal growth.
Sterility is the inability of an individual to produce offspring.
So, the correct answer is 'Addison's disease'.

The term Lipid was coined by Bloor. Lipids are the esters of fatty acid and alcohol. These are hydrophobic that is these are insoluble in water but soluble in benzene, ether and chloroform. As these are insoluble in water when they are added with water they separate to form two layers.

Nissl’s grains are mainly present in cyton and dendrite and absent in axons.

These granules are rough endoplasmic reticulum with rosettes of the free ribosome, the site for protein synthesis.

• Thalamus is the part of the brain that acts as a relay center to receive and transmit general sensations except for smell.
• It is located in the forebrain superior to the midbrain.
• It receives and processes almost all types of sensory information except for the sense of smell, which is processed by the olfactory bulb. 
• The thalamus then sends this information to the appropriate areas of the cerebral cortex, where it is further processed and interpreted.

The hypothalamus performs many functions which are important for the survival and enjoyment of life:

• It serves as a link between 'mind' and body and between nervous and endocrine system.
• The hypothalamus is responsible for hormone production. The hormone produced by this area govern body temperature thirst hunger, sleep, circulation rhythm, mood sex drive etc. This area of the brain also controls the functioning of the pituitary gland.
• Thus, if any injury localised to the hypothalamus it will disrupt the complete regulation of body temperature and other activities.

In our body, the neural and the endocrine system jointly coordinate and integrate all the activities of the organs so that they function in a synchronised fashion.

• Brain cavities are filled with cerebrospinal fluid (CSF). In subarachnoid space, the CSF acts as shockproof cushion to prevent injury in case of an accident.
• It also helps to distribute nutrients and remove waste products from the brain and spinal cord, and it helps to regulate the pressure inside the skull by providing a hydraulic cushion.

Coordination is the process through which two or more organs interact and complement the functions of one another. For example, the functions of muscles, lungs, heart, blood vessels, kidney, and other organs are coordinated while performing physical exercises.

• Nerve fibres do not show the property of elasticity and contractility. Nerve fibres are specialized to transmit impulses form one part of the body to other.
• These properties are typically associated with muscle cells. Elasticity refers to the ability of a material to return to its original shape after being stretched or deformed, while contractility refers to the ability of muscle cells to generate force and contract.

The thick segment of the ascending limb of Henle's loop extends as DCT. Cortical nephrons do not have vasa recta. PCT and DCT are situated in cortex of the kidney. Bowman's capsule encloses the glomerulus.

The dotted appearance of cortex of kidney is due to the presence of convoluted parts of the tubule (proximal and distal convoluted tubules).