Class 12th
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New answer posted
a year agoContributor-Level 10
The problem is to evaluate the integral:
I = ∫? ¹? [x] * e^ [x] / e^ (x-1) dx, where [x] denotes the greatest integer function.
The solution breaks the integral into a sum of integrals over unit intervals:
I = ∑? ∫? ¹ n * e? / e^ (x-1) dx
= ∑? n * e? ∫? ¹ e^ (1-x) dx
= ∑? n * e? [-e^ (1-x)] from n to n+1
= ∑? n * e? [-e? - (-e¹? )]
= ∑? n * e? (e¹? - e? )
= ∑? n * e? * e? (e - 1)
= (e - 1) ∑? n
= (e - 1) * (0 + 1 + 2 + . + 9)
= (e - 1) * (9 * 10 / 2)
= 45 (e - 1)
New answer posted
a year agoContributor-Level 10
Yes, candidate who have secured 60% in Class 12 board exams can secure an admission into BSc courses offered by the NIU. The candidates must clear Class 12 in the PCB stream to be eligible for most BSc courses and then appear for the CUET entrance exam to qualify for admissions. The NIU BSc admissions are decided through the CUET entrance exam.
New answer posted
a year agoContributor-Level 9
Fat-soluble vitamins are stored in our body for a relatively longer duration as compared to water-soluble vitamins.
- Vitamin B and C are water-soluble. (Thiamine is vitamin B1, while ascorbic acid is vitamin C).
- Vitamin A and vitamin D are fat-soluble, so they are stored in our body for a relatively longer duration.
New answer posted
a year agoContributor-Level 9
The E° value for Ce? /Ce³? is +1.74 V, which suggests that Ce? is a strong oxidant, reverting to its common +3 oxidation state. So, Ce³? is more stable than Ce?
New answer posted
a year agoContributor-Level 9
The size of the Bk³? ion is less than the Np³? ion because Berkelium (Bk) lies beyond Neptunium (Np) in the actinoid series, and the size variation here is because of the actinoid contraction.
New answer posted
a year agoContributor-Level 9
The enol form of acetone exists in less than 0.1% quantity, since its keto form is highly stable. But in the case of acetylacetone, the enol form is stabilized by intramolecular H-bonding, so its quantity increases to approximately 15%.
The intramolecular H-bond in the enol form of acetylacetone is shown.
New answer posted
a year agoContributor-Level 9
DIBAL-H at low temperature in a non-polar solvent, followed by hydrolysis, reduces esters to an aldehyde and an alcohol as a byproduct. The reaction shown is:
New answer posted
a year agoContributor-Level 10
Yes, total internal reflection can occur in both sound and water waves, including light waves, since it follows the same principle. Whenever a light/sound/water wave travels from denser to rarer medium and strikes the boundary of the medium at an angle greater than critical angle, the wave entirely reflects back into denser medium rather than refracting. Sonar waves in submarine reflect back entirely from the water surface as it hits at a steep angle. In water, ocean waves approach beach and slow down because of shallower water. If a wave hits the boundary of deep and shallow water at a steep angle, these waves will reflect back toward
New answer posted
a year agoContributor-Level 10
Let us take a look at the various applications of Total Internal Reflection in real life:
Total internal reflection is the foundational phenomenon used in modern telecommunications, internet cables and medical imaging. Light travels through thin and flexible fibres, which are made of glass and plastic. This light, then, undergoes Total internal reflection in the inner walls of the fibre, which allows travelling long distances with minimum loss.
Mirage is a phenomenon that occurs due to the total internal reflection as light gets reflected between the layers of air.
Diamonds shine because of total internal reflection. The gem is cut
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