Class 12th

Contributor-Level 10

Since direction of incident ray (DIR) is from left to write, so considering refraction at point M, we can write

$\frac{μ_{2}}{v} - \frac{μ_{1}}{u} = \frac{μ_{2} - μ_{1}}{R}$

-> $\frac{1.4}{v} - \frac{1.25}{- 40} = \frac{1.4 - 1.25}{- 25}$

$\Rightarrow - \frac{1.4}{v} = \frac{0.15}{25} + \frac{1.25}{40} = \frac{1.2 + 6.25}{200} = \frac{7.45}{200}$

$\Rightarrow v = - \frac{200 * 1.4}{7.45} = - 37.58 c m$

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5 months ago

The passage below is accompanied by a set of questions. Choose the best answer to each question.

Plasma is the often-forgotten part of blood. White blood cells, red blood cells, and platelets are important to body function. But plasma also plays a key role. This fluid carries the blood components throughout the body.

Plasma is the largest part of your blood. It makes up more than half (about 55%) of its overall content. When separated from the rest of the blood, plasma is a light-yellow liquid. Plasma carries water, salts and enzymes.

The main role of plasma is to take nutrients, hormones, and proteins to the parts of the body t

The passage below is accompanied by a set of questions. Choose the best answer to each question.

The main role of plasma is to take nutrients, hormones, and proteins to the parts of the body that need it. Cells also put their waste products into the plasma. The plasma then helps remove this waste from the body. Blood plasma also carries all parts of the blood through your circulatory system.

Plasma is a critical part of the treatment for many serious health problems. This is why there are blood drives asking people to donate blood plasma.

Along with water, salt, and enzymes, plasma also contains important components. These include antibodies, clotting factors, and the proteins albumin and fibrinogen. When you donate blood, healthcare providers can separate these vital parts from your plasma. These parts can then be concentrated into various products. These products are then used as treatments that can help save the lives of people suffering from burns, shock, trauma, and other medical emergencies.

The proteins and antibodies in plasma are also used in therapies for rare chronic conditions. These include autoimmune disorders and haemophilia. People with these conditions can live long and productive lives because of the treatments. In fact, some health organisations call plasma "the gift of life."
If you want to donate plasma to help others in need, you will go through a screening process. This is to make sure your blood is healthy and safe. If you qualify as a plasma donor, you'll spend about an hour and a half at a clinic on every follow-up visit.

During the actual blood donation process, your blood is drawn through a needle placed in a vein in one arm. A special machine separates the plasma and often the platelets from your blood sample. This process is called plasmapheresis. The remaining red blood cells and other blood components are then returned to your body, along with a little saline (salt) solution.

People with the blood type AB are in the greatest demand for plasma donation. They make up just 2 in 50 people, their plasma is universal. This means their plasma can be used by anyone.

Plasma donation requires a commitment both in the amount of time for each donation and frequency of donation. Typically, it takes between one and three hours to donate source plasma, and plasma can be donated twice within a seven-day period. Whole blood donation takes less time—under 30 minutes—and donors donate less frequently—no more than once in eight weeks. The programs may fit into a donor's life differently at various times in the donor's life, and are equally important in helping to fulfill a vital medical need.

All of the following statements weaken the author's understanding of plasma donation EXCEPT:

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Class 12th Electromagnetic Induction

Contributor-Level 10

Option C can be inferred from the following lines of the 7^th paragraph “If you qualify as a plasma donor, you'll spend about an hour and a half at a clinic on every follow-up visit.”. Here, the condition-based conjunction makes it evident that it is necessary to qualify screening process. Other options are either untrue or signify less reliable facts.

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5 months ago

The arm PQ of a rectangular conductor is moving from x = 0 to x = 2b outwards and then inwards from x = 2b to x = 0 as shown in the figure. A uniform magnetic field perpendicular to the plane is acting from x = 0 to x = b. Identify the graph the variation of different quantities with distance.

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Contributor-Level 10

When arm PQ of a rectangular conductor is moving from x = 0 to x = b, the flux $(? = a x)$ linked with loop increases and while moving from x = b to x = 2b and from x = 2b to x = b, $(? = a b)$ flux remains constant and then flux $(? = a x)$ decreases to zero as it moves from x = b to x = 0.

$e_{i n} = - \frac{d ?}{d t} = - a \frac{d x}{d t} = - a v \Rightarrow$ Induced emf

$P = \frac{{(e_{i n})}^{2}}{R} \Rightarrow$ Power dissipated

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5 months ago

The passage below is accompanied by a set of questions. Choose the best answer to each question.

The main role of plasma is to take nutrients, hormones, and proteins to the parts of the body t

The passage below is accompanied by a set of questions. Choose the best answer to each question.

Plasma is a critical part of the treatment for many serious health problems. This is why there are blood drives asking people to donate blood plasma.

Which one of the following comes closest in meaning to the author's understanding of plasma?

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Contributor-Level 10

Option A and C are misinterpreted facts and Option D specifically talks about its usage. The true meaning has been conveyed in the second option which is more near to author's understanding as per the passage.

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5 months ago

Class 12th Physics

For the circuit shown below, calculate the value of I₂

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Contributor-Level 10

$l_{1} = \frac{50}{2000} = 25 m A, a n d l = \frac{V_{i} - V_{Z}}{1000} = \frac{100 - 50}{1000} = 50 m A$

$\Rightarrow l_{z} = l - l_{1} = 25 m A$

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5 months ago

There is a sentence that is missing in the paragraph below. Look at the paragraph and decide in which blank (option 1, 2, 3, or 4) the following sentence would best fit.

Sentence: This doesn't mean you won't ever be able to access it

ChatGPT is still free to use. (1)__________. Because of the stir its advanced capabilities have made, many people are flocking to use it. (2)___________. The website operates using a server, and when too many people hop onto the server, it overloads and can't process your request. (3)___________. It just means you should try visiting the site at a later time when fewer people are trying to access the serve

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Class 12th Dual Nature of Radiation and Matter

Contributor-Level 10

The sentence before 3^rd states a problem related to ChatGPT and the given statement provides a solution.

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The radiation corresponding to 3->2 transition of a hydrogen atom falls on a gold surface to generate photoelectrons. These electrons are passed through a magnetic field of 5 * 10^-4 T. Assume that the radius of the largest circular path followed by these electrons is 7mm, the work function of the metal is: (Mass of electron = 9.1 * 10^-31 kg)

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Contributor-Level 10

$h ν = 3.4 - 1.51 = 1.89 e V$

As we know that radius of circular path in magnetic field is given as

$r = \frac{\sqrt[]{2 m K}}{q B} \Rightarrow K = \frac{r^{2} q^{2} B^{2}}{2 m}$

$\Rightarrow K = \frac{{(7 * 1 0^{- 3})}^{2} * (1.6 * 1 0^{- 19}) * {(5 * 1 0^{- 4})}^{2}}{2 * 9.1 * 1 0^{- 31}} e V = 107.7 * 1 0^{- 2} e V$ = 1.08 eV

$\Rightarrow ? = h ν - K = 1.89 - 1.08 = 0.81 e V$

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5 months ago

There is a sentence that is missing in the paragraph below. Look at the paragraph and decide in which blank (option 1, 2, 3, or 4) the following sentence would best fit.

Sentence: Therefore, over time, there will be more copies of these mutants than other molecules.

(1)____________.The “RNA world” hypothesis suggests that early life may have used RNA as material for both genes and replication before the emergence of DNA and proteins. (2)___________. Once an information system can make copies of itself, natural selection kicks in. (3)_________. Some of the new copies of these molecules (which some would call “genes”) will

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Contributor-Level 10

The given sentence concludes the statement given before the 4^th blank. Hence, it meaningfully fits in the 4^th blank only.

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Class 12th Physics

The value of current in the $6 Ω$ resistance is:

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