Daily NEET MCQ- August 26, 2022 - NEET MCQ

All elements in the elementary state have an oxidation number of zero. So helium element also has an Oxidation state of zero. It is one of the most important points for determining the oxidation number.

In all compounds except ionic metal hydride the oxidation number of hydrogen is +1. But in metal hydrides like sodium hydride, magnesium hydride, calcium hydride, etc, the oxidation number of hydrogen as -1.

Dividing into two parts oxidation number of N in NH₄⁺ is x; x + 4*1 = +1; x = -3, oxidation number of N in NO₃^– is y; y + 3*-2 = -1; y = 5. The oxidation States of Nitrogen in this compound are -3 and 5 respectively.

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 pressure in the bubble will be more than the pressure just outside it by an amount 2S/R.
The pressure just outside the bubble is P₀ + ρgh.
Therefore, pressure inside bubble = P₀ + ρgh + 2S/R
= 10⁵ + (1000*10*1) + (2*0.075/0.01)
= 110015 Pa.

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.

The process of photosynthesis has two stages-the light reaction and the dark reaction. The products of the light reaction are oxygen, ATP and NADPH. The light reaction requires light to carry out its reactions.

The process of photosynthesis has two stages-the light reaction and the dark reaction. The products of the light reaction are oxygen, ATP and NADPH. Oxygen diffuses out of the chloroplast.

Melvin Calvin has contributed greatly to photosynthesis studies. The Calvin cycle was named after him. He first identified the compound PGA or 3-phosphoglyceric acid as a product of photosynthesis.

Melvin Calvin has contributed greatly to photosynthesis studies. The Calvin cycle was named after him. He used radioactive C-14 to discover the first CO₂ fixation product of photosynthesis, PGA.