Explanation:

Momentum doesn’t change i.e.
(2m)*(v/2).
K.E decreases by half while
P.E becomes twice the original value.

Explanation:

Apply law of momentum conservation

3mv = m*0 + 2mv'

v= 2v'/3

v' = 3v/2

Explanation:

An aerofoil is designed so that air flows faster over the curved top, reducing pressure and creating lift perpendicular to the direction of motion.

Explanation:

Heat lost: Q = −20 J
Work done on gas means work by gas is negative: W = −60 J
ΔU = Q − W = (−20) − (−60) = +40 J

Explanation:

=76

According to Newton's third law, the forces on the two objects are equal in magnitude and opposite in reaction. Such forces cause one object to gain momentum and the other object to lose momentum such that total momentum of the system remains conserved in absence of any external force.

Hence, newton's third law of motion leads to law of conservation of momentum.

Explanation:

Work done = gain in potential energy
= mgh = 50 × 10 × 3
= 1500 J.

Power = Work / Time
= 1500 / 5
= 300 W.

The $P-V$ diagram of adiabatic process, isothermal process and isobaric process are shown in (figure).

Work done in process= area enclosed by $P-V$ diagram with volume axis.
Since area under the curve is maximum for adiabatic process, so work done on the gas will be maximum for adiabatic process.

Explanation:

Torricelli’s theorem is derived by applying Bernoulli’s equation between the fluid surface and the leak point, assuming steady, ideal flow.

Explanation:

An engine carburetor is designed to blend air and fuel in proper proportions for combustion in an internal combustion engine.

u = 4m/s           

v=0           
t=2sec
a=?

v=u+at
0=8+a(2)
a=−4m/s2
so,
F = ma
=4×4=16N

Explanation:

Newton second law explain the concept of Force

F=ma

Explanation:

Cross product is zero if vectors are parallel (θ = 0° or 180°) or if either vector is a zero vector.
Because sin0° = sin180° = 0.

Explanation:

In one complete cycle, the particle comes back to the initial velocity. Displacement is zero, therefore average velocity is also zero.

NOTE: it's a Recall Based MCQs (Just remember it)

Acceleration = Aω²sin ωt The phase difference between acceleration and velocity is π/2.

Explanation:

Explanation:

Aerofoils are used in flying and rotating systems like wings, blades, and propellers not in static vision instruments like submarine periscopes.

Explanation:

The dislodged plaque can travel and block a smaller artery, leading to a heart attack.

ΔQ = ΔU + ΔW

ΔW = ΔQ - ΔU

= 410 - 40 = 370 J

Explanation:

Magnitude of cross product = |A||B|sinθ
Since vectors are perpendicular, θ = 90°, sin90° = 1.
So magnitude
= 4 × 6 × 1 = 24.

its the unit of momentum
P=mv
p=kg m/s
and 
P is also equal to impulse which is 
F.t
alternate unit is 
Ns

Explanation:

A stretched string can support two types of mechanical waves.

Transverse waves
The string elements move perpendicular to the length of string, these are the common waves on a string.

Longitudinal waves
If the string is stretched and compressed along its length, particles vibrate parallel to the length, so longitudinal waves can also exist in the string material.

Therefore both transverse and longitudinal waves can exist.

Internal energy depends only on the initial and final states of temperature and not on the path. 

In a cyclic process, as initial and final states are the same, change in internal energy is zero (ΔE = 0).

Hence E is ΔU, the change in internal energy.

Explanation:

Faster airflow creates an even lower pressure region above the paper, increasing the pressure difference and lifting it higher.

Explanation:

Explanation:

The first vaccine was developed by Edward Jenner, an English physician, in 1796.

Jenner is credited with developing the first vaccine for smallpox, a highly infectious and deadly disease that killed millions of people over the centuries. Jenner observed that milkmaids who had contracted cowpox, a less severe disease, seemed to be protected from smallpox. He tested his theory by inoculating a young boy with cowpox and then exposing him to smallpox. The boy did not develop smallpox, and Jenner concluded that cowpox could protect against smallpox.

Explanation:

Rheumatoid arthritis is an autoimmune disease that causes chronic inflammation in the joints and other parts of the body.In rheumatoid arthritis, the immune system mistakenly attacks the body's own tissues, particularly the synovial membrane that lines the joints. This leads to inflammation, which can cause pain, swelling, stiffness, and reduced mobility in the affected joints.

Explanation:

The BCG vaccine is a live attenuated vaccine.

The BCG vaccine, which stands for Bacille Calmette-Guérin, is a vaccine that is used to protect against tuberculosis (TB). It is made from a weakened form of Mycobacterium bovis, which is a related bacterium to the one that causes TB in humans.

esterase, phosphatase and peptidases are the example of hydrolases

a heterogenous group of enzyme which convert one isomer into another isomeric form is called isomerase. e.g mutase

Explanation:

• Enzymes can create a microenvironment inside the active site that differs from the surrounding solution.
• This allows optimal pH, polarity, or ionic conditions for catalysis even if the external environment is different.
• Such local conditions help stabilize the transition state and increase reaction rate.
• The rest of the enzyme and solution may have neutral or different conditions, but the active site is tuned for efficiency.
• Therefore, enzymes modify conditions inside the active site relative to the outside environment.

Explanation:

Alcoholic fermentation is brought about by micro organisms

Explanation:

In aerobic respiration, one glucose molecule is fully oxidized to CO₂ and H₂O in the presence of oxygen, producing ATP in three stages:
Glycolysis: 2 ATP (direct) + 2 NADH → 6 ATP = 8 ATP
Link Reaction: 2 NADH → 6 ATP
Krebs Cycle: 6 NADH → 18 ATP, 2 FADH₂ → 4 ATP, 2 ATP (direct) = 24 ATP
Total: 8 + 6 + 24 = 36 ATP per glucose molecule.

Explanation:

Anaerobic respiration (like in muscle cells during oxygen shortage or in yeast) involves only glycolysis.
Glycolysis produces 2 ATP molecules per glucose.
Since there’s no oxygen, the process does not proceed to the Krebs cycle or oxidative phosphorylation, which produce more ATP in aerobic respiration.

Explanation:

Lactic acid fermentation occurs in the muscles of humans. When the demand for energy (ATP) exceeds the supply of oxygen, such as during intense physical exercise, the muscles can undergo lactic acid fermentation as a temporary means to produce ATP

Explanation:

When oxygen is available, pyruvate enters the mitochondria for aerobic respiration.
It is completely oxidized in the Krebs cycle and electron transport chain, producing:
CO₂ → released during the link reaction and Krebs cycle.
Water (H₂O) → formed when oxygen acts as the final electron acceptor in the ETC.
ATP → up to ~36–38 ATP per glucose molecule (depending on the shuttle system and cell type).
Hence, all three listed products are formed.

Explanation:

The measles virus spreads through airborne droplets released when an infected person coughs or sneezes, making it highly contagious.

Explanation:

The measles virus has a negative-sense single-stranded RNA genome, which requires conversion into a positive-sense strand for protein synthesis.

Explanation:

Viroids primarily infect plants, causing diseases and distorted growth. They do not affect protein synthesis but replicate and produce specific RNA molecules.

Explanation:

The Potato spindle tuber viroid was the first identified viroid. It is one of approximately 33 known species of viroids that infect plants.

Explanation:

The rabies virus infects the central nervous system of mammals.

It can affect humans, dogs, cats, bats, foxes, cattle, and other mammals.

Birds, reptiles, amphibians, and fish are not affected because the virus cannot replicate in them.

Therefore, its host range is limited to mammals only.

Explanation:

Dengue is caused by the Dengue virus, a member of the Flaviviridae family.

It is transmitted to humans through the bite of Aedes aegypti and Aedes albopictus mosquitoes.

It is not caused by fungi, bacteria, or protozoa.

Explanation:

The word “immune” is derived from the Latin word, originally meaning “exempt” or “free” from certain responsibilities or burdens.

Explanation:

The spleen is often referred to as the "graveyard of red blood cells." This is because one of its functions is to remove old or damaged red blood cells from circulation, breaking them down and recycling their components.

Explanation:

The epicardium is  made of a serous membrane. It's the outermost layer of the heart wall and is composed of a layer of simple squamous epithelium (mesothelium) and underlying connective tissue.

Explanation:

Heart are found 9 cm from mid line on left side

Explanation:

The apex of the heart typically extends to the fifth intercostal space, which is located between the fifth ribs. This is where the lower tip of the heart rests against the chest wall.

Explanation:

There are two main types of lymphocytes: B cells and T cells. The B cells produce antibodies that are used to attack invading bacteria, viruses, and toxins.

Explanation:

Once stimulated by the appropriate antigen, helper T cells secrete chemical messengers called cytokines, which stimulate the differentiation of B cells into plasma cells, thereby promoting antibody production.

Explanation:

Active immunity develops in an organism when exposed to a specific antigen, that is, the organism produces antibodies in response to a foreign antigen. However, the antibody production may not be quick but is long lasting.
So, the correct answer is 'Active immunity is quick and gives full response.'

Explanation:

heart is composed of special type of muscle called cardiac muscle or myogenic muscle. they are striated and involuntary

Explanation:

The lymphatic system collects excess fluid from tissues, transporting it through vessels and nodes. Lymph nodes filter and cleanse the lymph, and the system returns it to the bloodstream for fluid balance and immune support. Additionally, the lymphatic system aids in transporting fats and fat-soluble vitamins from the digestive system to the blood.

Explanation:

Olaus Rudbeck first described lymphatic ducts in liver

Explanation:

The cardiovascular system is responsible for distributing blood throughout the body, ensuring that oxygen, nutrients, hormones, and other vital substances reach all the cells and tissues while also removing waste products.

Explanation:

the myocardium of the left ventricle is typically the thickest among the heart chambers. This is because the left ventricle is responsible for pumping oxygenated blood to the rest of the body, and it needs to generate enough force to overcome the resistance of the systemic circulation

Explanation:

In humans, oxygenated blood is pumped from the left atrium to the left ventricle and then into the aorta, supplying the entire body with oxygen

Explanation:

The sound produced by heart is generally verbalized  as lub dub

Explanation:

One complete cardiac cycle takes 0.8 seconds

Explanation:

the pacemaker of the heart, specifically the sinoatrial (SA) node, is typically located in the upper dorsal part of the right atrium near the opening of the superior vena cava.

Explanation:

A capillary is so thin that only one RBC passes through it at a time

Explanation:

the vessels which bring the blood back from different organs of the body towards heart are called as  veins

Explanation:

HIV (Human Immunodeficiency Virus) primarily targets and infects CD4 T cells, a type of white blood cell that plays a central role in the immune system.

Explanation:

carbohydrates are called as polyhydroxy aldehydes and ketones or substances which yield such compounds on hydrolysis. carbohydrates contain either aldehyde or ketone as a functional groups attached to one of the carbon atoms 

Explanation:

lipids do contain a higher proportion of carbon-hydrogen (C-H) bonds compared to other biomolecules like carbohydrates and proteins.

Explanation:

The triesters of fatty acids with glycerol (1,2,3-trihydroxypropane) compose the class of lipids known as fats and oils. These triglycerides (or triacylglycerols) are found in both plants and animals

Explanation:

Most of fatty acids in a cell contain 16-18 carbon atom per molecule

Explanation:

A phospholipid molecule consists of two main parts: a hydrophilic head and two hydrophobic tails

Explanation:

In a phospholipid molecule a phosphate head is polar in nature

Explanation:

In a phospholipid molecule the hydrophilic head contains a phosphate group and is attracted(soluble) to water

Explanation:

Each steroid is formed of a backbone of four fused carbon rings containing 17 carbon atoms

Explanation:

Lipids are the building material of cellular membranes called lipoprotein membrane

Explanation:

The nucleolus is a ribosome production factory, designed to fulfill the need for large-scale production of rRNAs and assembly of the ribosomal subunits.

Explanation:

both mitochondria and chloroplasts have 70S ribosomes. These ribosomes are structurally similar to prokaryotic ribosomes and differ from the 80S ribosomes found in the cytoplasm of eukaryotic cells. 

Explanation:

Autophagy is indeed often described as a "cell eating" process. It is a cellular mechanism by which cells degrade and recycle their own components, including damaged organelles and proteins

Explanation:

The Ebola virus is harbored by animals like bats, dogs, and canids, and transmission occurs through contact with infected body fluids or tissues.

first enzyme was discovered by Anselme Payen in 1833 and the enzyme was carbohydrate digesting enzyme called diastase

Explanation:

Hodgkin's disease, or Hodgkin's lymphoma, can indeed result in the enlargement of lymph nodes in various parts of the body, including the neck. Enlarged lymph nodes in the neck are a common symptom of Hodgkin's disease

Explanation:

Large lymphatic vessels that collect lymph from smaller lymphatic vessels are typically referred to as "lymphatic trunks." These lymphatic trunks converge and eventually form the two main lymphatic ducts in the body: the thoracic duct and the right lymphatic duct

Explanation:

lymph nodes in the axillary region are located in the underarm or armpit area. These axillary lymph nodes are an essential part of the lymphatic system and play a crucial role in filtering and draining lymph from the upper extremities

Explanation:

Lymph vessels have masses of connective tissue called "lymph nodes" at certain points along their course. Lymph nodes are small, bean-shaped structures that are part of the lymphatic system.

Explanation:

lymphatic ducts were first discovered in liver

Explanation:

The ventricles of the heart are the lower chambers, and they are larger and thicker-walled compared to the atria. The left ventricle is typically thicker and more muscular than the right ventricle because it pumps oxygenated blood to the body's systemic circulation, which requires more force.

Explanation:

The myocardium is the middle layer of the heart wall and consists of specialized cardiac muscle cells responsible for contracting and pumping blood throughout the body. These muscle fibers in the myocardium are responsible for the heart's rhythmic contractions

Explanation:

The myocardium is the layer of the heart that contains the contractile element of the heart. It is made up of specialized cardiac muscle cells (cardiomyocytes) responsible for the contraction of the heart

Explanation:

The heart has three main layers: the outermost epicardium, the middle myocardium (which is responsible for pumping blood), and the inner endocardium. The endocardium is a smooth, thin, and delicate lining that covers the heart's chambers and valves

Explanation:

The human heart is found in the thoracic cavity . The heart is positioned slightly to the left of the midline, so it is more commonly felt and heard on the left side of the chest. It is located between the two lungs and sits behind the sternum (breastbone)

Explanation:

Membrane carbohydrates play a crucial role in endocytosis, pinocytosis, and phagocytosis by serving as recognition and signaling molecules. 

Explanation:

in cytosol some large molecules form colloidal solution which is of two type i-e sol (non -viscous) or gel ( jelly like or viscous). often the outer region of cytoplasm is more gel like 

Explanation:

membrane proteins makes plasma membrane selectively permeable barrier that select materials according to the cell's need

Explanation:

the secondary wall follows the order of  primary wall in development. it is laid down inside the primary wall

Explanation:

primary cell wall is the first wall formed in a developing cell. it is usually 1-3μm in thickness. more or less elastic and extendable , crystalline and optically active

Cellulose and chitin are indigestible polysaccharides for humans due to their complex structures.Both lack the specific enzymes needed for efficient breakdown in the human digestive system.

Explanation:

sucrose is hydrolyzed into its constituent monosaccharides, glucose and fructose. This hydrolysis reaction involves breaking the glycosidic bond that connects the glucose and fructose molecules in sucrose

Explanation:

Protoplasm cannot survive if its water content is reduced as low as 10%

Explanation:

Carbohydrates are called "hydrated carbon" due to their composition of carbon, hydrogen, and oxygen in a 2:1 ratio, similar to water. They are also referred to as "polyhydroxy aldehydes and ketones" because they contain multiple hydroxyl groups (-OH) and either an aldehyde or ketone functional group, defining their chemical structure. 

Explanation:

HIV is surrounded by a coat of lipoprotein known as the viral envelope or membrane. This envelope is derived from the host cell membrane as the virus buds out of the infected cell during its replication cycle.the envelope is studded with viral glycoproteins, including gp120 and gp41, which are essential for attaching to and fusing with host cell receptors during the process of viral entry.

Explanation:

The core of the HIV virus is formed from a protein called p24 (also known as the Capsid protein). The p24 protein is a product of the gag gene of HIV, and it plays a central role in the structure and function of the viral core.

Explanation:

HIV (Human Immunodeficiency Virus) replicates using a process that involves the conversion of its RNA genome into DNA. This conversion is carried out by an enzyme called reverse transcriptase.

Explanation:

HIV (Human Immunodeficiency Virus) is a retrovirus, and its structure includes various proteins. One of these proteins is p17, also known as the HIV Matrix protein.

Explanation:

Tobacco mosaic virus (TMV; Tobamovirus, Virgaviridae) is a rodlike virus with a length of 300 nm and diameter of 18 nm.

HINT: Use general expression for second order kinetics.

STEP 1:  The reaction X → Y follows second order kinetics.

Rate = k[X]²

STEP 2: If concentration of X increases 3 times i.e. [X'] = [3X]

Rate = k [X']² = 9 K[X]²

Hint: Intermediate formed in the first reaction and consumed in the second reaction

An intermediate is a molecule that is formed from two or more reactants and then reacts further to give products. An intermediate may be an unstable molecule (a reactive intermediate) or a highly stable molecule. 

Intermediate consumed in the reaction. It cannot be mentioned in the final reaction equation.  

O atom is an intermediate because it forms in the first reaction and is consumed in the second reaction.

 Due to the see-saw shape of SF₄,  $\mu$  0 . All other molecules have zero dipole moment.

Conditions for Writing Resonating Structures: 

(i) The contributing structures should have same atomic positions. 

(ii) These structures should have same number of unpaired electrons. 

(iii) These structures should have nearly same energy. 

(iv) These structures should be written such that negative charge is present on an electronegative atom and positive charge is present on an electropositive atom. 

(v) In contributing structures, like charges should not reside on adjacent carbon.

(vi) Hybrid structure is least energetic.

HINT: Central atom octet is not complete in electron - deficient species.

$N^{}{H}_3,P^{}{H}_3$ - electron-rich species, because the central atom has the lone pair. Nitrogen in ammonia and phosphorus in ${\mathrm{PH}}_3$ are central atoms and their octet is complete.

${\mathrm{CH}}_3-{\mathrm{CH}}_3$ is a Covalent neutral molecule and carbon octet is also complete .

But in the case of ${\mathrm{BH}}_3$ boron octet is not completed, it has only 6 electrons in its valence shell. So, it is an electron-deficient species.

HINT: For the same n value, the strength of overlapping is p-p > s-p > s-s

Bond strength depends upon two factors :

(i) Size of orbitals (ii) Extent of overlapping

Thereby, σ bond is always stronger than π bonds. The smaller the size of orbitals, stronger is
the bond.

When the n value is the same then p-p overlapping is stronger than s-p and s-s.

The order of bond strength can be explained on the basis of the fact that the more the area of overlap, the higher will be the strength. Since the p orbital has directional property, p – p overlap provides more area for overlap for the same internuclear distance.

In H-bonding, a hydrogen atom should be attached to a more electronegative atom.

In ${\mathrm{CH}}_{3}F$, hydrogen bonding did not occur because hydrogen is attached to a carbon atom and carbon atom is not an electronegative element.

Among H2O,H2S,H2Se and H2Te, the one with the highest boiling point is H2O because of intermolecular hydrogen bonding which leads to molecular association and leads to higher energy for boiling.

Causes of deviations from ideal behaviour is due to the following assumptions:

$\left(1\right)$. Volume occupied by gas molecules is negligible as compared to volume occupied by the gas.

$\left(2\right)$. The forces of attraction between gas molecules are negligible.

A real gas behaves as an ideal gas at low pressures and high temperature.

only in ISOTHERMAL PROCESS the temperature is constant hence boyle's law is valid.

The beans are cooked earlier in a pressure cooker because the boiling point increases with increasing pressure. That means food can cook at much higher temperature and since cooking reaction speeds up at higher temperatures, food cooks faster.

Hint: Gap in transition line should be low and transittion should be from lower to higher.

VIDEO EXPLANATION:

As we go up in hydrogen spectrum, the energy differences decrease and wavelength increases.

Absorption line in the spectra arises when energy is absorbed i.e., electron shifts from lower to higher orbit, out of option 1 and 2, 2 will have the lowest frequency as this falls in the Paschen series.

The higher the value of (n + l) for an orbital, the higher is its energy.

However, if two different types of orbitals have the same value of (n + l), the orbital with the lower value of n has lower energy.

Therefore, decreasing order of energy of the given orbitals is 5f > 6p > 5p > 4d.

Only 1s orbital is present in 1st shell.
Only 2s,2p orbitals are present in 2nd shell.
Only 3s, 3p,3d orbitals are present in 3rd shell.
Only 4s, 4p,4d and 4f orbitals are present in 4th shell.
So 1p and 3f do not exist

Maximum number of electrons in a subshell of an atom can be determined by which of the following formula 4l + 2

Hint: Draw the orbital diagram and find the number of unpaired electron.

In this type of electronic configuration the number of unpaired electrons are 3. The orbital diagram is as follows:

n = main energy level
l= subshell
If n = 4 and l = 3, the subshell is 4f. In f subshell, there are 7 orbitals and each orbital can accommodate a maximum of two electrons, so, maximum no. of electrons in 4f subshell = 7 x 2 = 14.

The number of orbitals associated with principal quantum number n is n² $={52}^{}=25$.

Convert Gram into moles and 
from balance chemical equation we can see that

now 120 g of CO2 produced a smaller number of moles of H2CO3 so it is limiting reagent

Oxygen composition is almost 65 while hydrogen is 2
so the ratio is almost 32