All questions of December Week 1 for NEET Exam

Because which contains Nictogen and other harmful compounts which can affect our whole body it supress our body function

 An extensive variable is one which depends on system size (like mass or volume). ... An intensive variable is one which does not depend on system size (like temperature, pressure, or density).

Direct respiration means exchange of gases without using any special respiratory organ and blood. In case of insects, the tracheal tubes exchange oxygen and carbon dioxide with the haemocoel which then exchange then with tissues

's law
b)Boyle's law
c)Gay-Lussac's law
d)Joule's law

d) Joule's law.

Gas exchange during respiration occurs primarily through diffusion. Diffusion is a process in which transport is driven by a concentration gradient. ... The air in thelungs has a higher concentration of oxygen than that of oxygen-depleted blood and a lower concentration of carbon dioxide.

Understanding the Problem
A body with a mass of 2 kg is being dragged on a horizontal surface at a constant speed of 2 m/s. The coefficient of friction between the body and the surface is 0.2. We need to find the heat generated due to friction over a period of 5 seconds.
Calculating the Force of Friction
- The formula for the force of friction (F_friction) is given by:
- F_friction = coefficient of friction * normal force
- For a horizontal surface, the normal force (N) equals the weight of the body:
- N = mass * g (where g is approximately 9.81 m/s²)
- Therefore:
- N = 2 kg * 9.81 m/s² = 19.62 N
- F_friction = 0.2 * 19.62 N = 3.924 N
Calculating Work Done Against Friction
- Work done (W) against friction is given by:
- W = F_friction * distance
- The distance traveled in 5 seconds at 2 m/s:
- Distance = speed * time = 2 m/s * 5 s = 10 m
- Thus, the work done:
- W = 3.924 N * 10 m = 39.24 J
Converting Work to Heat
- The heat generated (Q) is equal to the work done against friction.
- To convert joules to calories, use the conversion factor:
- 1 cal = 4.184 J
- Converting the work done to calories:
- Q = 39.24 J / 4.184 J/cal ≈ 9.38 cal
Final Answer
- Rounding off gives approximately 9.33 cal, which corresponds to option D.
In conclusion, the heat generated due to friction in this scenario is approximately 9.33 calories.

Respiration is the process by which living organisms exchange gases with the environment. The correct sequence of respiration is as follows:

i) Breathing in oxygen
ii) Diffusion of gases across alveolar membrane
iii) Transportation of gases by the blood
iv) Diffusion of gases between blood and tissues
v) Using of oxygen and releasing of carbon dioxide

Explanation:

i) Breathing in oxygen: The process of respiration begins with the inhalation of air which contains oxygen. The air enters the body through the nostrils and mouth and travels down the trachea to reach the lungs.

ii) Diffusion of gases across alveolar membrane: In the lungs, oxygen diffuses across the alveolar membrane and enters the bloodstream. At the same time, carbon dioxide from the blood diffuses across the alveolar membrane and enters the lungs to be exhaled.

iii) Transportation of gases by the blood: The oxygen-rich blood is transported by the circulatory system to all parts of the body where it is needed for cellular respiration. The carbon dioxide produced by cellular respiration is transported back to the lungs by the blood to be exhaled.

iv) Diffusion of gases between blood and tissues: In the tissues, oxygen diffuses from the blood into the cells, while carbon dioxide diffuses from the cells into the blood.

v) Using of oxygen and releasing of carbon dioxide: Inside the cells, oxygen is used in cellular respiration to produce energy, while carbon dioxide is produced as a waste product. This carbon dioxide is transported back to the lungs to be exhaled, and the process of respiration starts again.

Therefore, the correct sequence of respiration is i) Breathing in oxygen, ii) Diffusion of gases across alveolar membrane, iii) Transportation of gases by the blood, iv) Diffusion of gases between blood and tissues, and v) Using of oxygen and releasing of carbon dioxide.

Understanding Isothermal Processes
In an isothermal process, the temperature remains constant while a gas expands or contracts. The work done during this process can be derived from the first law of thermodynamics and the ideal gas law.
Work Done in Isothermal Process
- The formula for work done (W) when a gas expands or compresses is given by:
W = ∫ P dV
- For an ideal gas, pressure (P) can be expressed using the ideal gas equation:
P = nRT/V
- Substituting this into the work integral, we have:
W = ∫ (nRT/V) dV
- This integration occurs from the initial volume (V1) to the final volume (V2).
Integrating the Expression
- The work done then simplifies to:
W = nRT ∫ (1/V) dV from V1 to V2
- Performing this integral yields:
W = nRT [log(V2) - log(V1)]
- This can be further simplified using logarithmic properties:
W = nRT log(V2/V1)
Per Mole of Gas
- Since the question asks for the work done per mole, we set n = 1 (per mole):
W = RT log(V2/V1)
- To express this in terms of natural logarithms, we recognize that:
log(a/b) = log(a) - log(b)
Final Answer
- Thus, the correct expression for work done per mole during an isothermal process is:
W = RT loge(V2/V1)
This corresponds to option 'C', confirming that the work done is related to the natural logarithm of the volume ratio during an isothermal expansion or compression.

The main regulation center responsible for respiration is medulla oblongata and pons virolli which lie in brain.