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Correct Answer is: (a) in all cases 

Correct Answer is: (a) the maximum value R/4 , (c) the minimum value R (n - 1/n²)

The resistance of each side = R/n.

For resistance between opposite corners, we have two resistors of resistance R/2 in parallel.

For resistance between adjacent corners, we have two resistors of resistances R/n and (n - 1) R/n in parallel.

The correct answer is (a) 2Ω.

Drones possess 16 chromosomes. Mitosis is involved in the production of sperms.

This syndrome develops due to trisomy (2x + 1) of chromosome 21. The non-disjunction of the 21 chromosome during meiosis causes the trisomy of 21st chromosome and results in Down's syndrome.

Cause-sex-linked recessive disorder 

Symptoms-failure to discriminate between red and green colour

Detailed answer:

The colour blindness is due to recessive sex linked disorder. In this disorder of vision the patient is unable to distinguish between red and green colour. The gene for colour blindness is located on the X chromosome.

16 chromosomes do drones of honeybee possess, Mitosis cell division involved in the production of sperms by them.

(i) Autosomal, recessive gene, gene for alpha thalassemia is on chromosome 16, for Beta thalassemia it is on chromosome 11.

(ii) Cause of symptoms-Mutation or deletion of the gene / genes, resulting in reduced rate of synthesis of one of the globin chains / alpha or beta chains.

(iii) Thalassaemia is a quantitative problem/ of too few globin molecules of haemoglobin, while sicklecell is a qualitative problem of synthesizing an incorrectly functioning globin.

11th and 16th chromosomes carry the mutant gene causing thalassaemia.

These cause the formation of abnormal haemoglobin molecules into anaemia.

1. HBA1 gene is located on chromosome 16. 

2. HBB gene is located on chromosome 11.

The potential energy of a hydrogen atom is zero in ground state.

An electron is board to the nucleus with energy 13.6 ev.,

Show we have to give energy of 13.6 ev. To cancel that energy.

Then additional 10.2 ev. is required to attain first excited state.

Total energy of an atom in the first excited state is = 13.6 ev. + 10.2 ev. = 23.8 ev.

Similarities between Chromosomes and Genes: 

1.  Both occur in pairs.

2.  Both segregate at the time of gamete formation such that only one of each pair is transmitted to a gamete.

3.  Independent pairs segregate independently of each other in both.

K = 8.62 x10^–5 eV/k

K.E. of H₂ molecules = 3/2 KT

Energy released, when atom goes from ground state to no = 3

=>13.6 (1/1 – 1/9) => 3/2 KT = 13.6(1/1 – 1/9)

=> 3/2 x 8.62 x 10^-5 T=13.6 x 8/9

=>T=0.9349 x 10⁵=9.349 x 10⁴=9.4 x 10⁴K.

Correct answer is (c) H₂S

(1) False. Molecular state of oxygen is diatomic.

(2) True 

(3) False. Anionic radicals are acidic radicals. 

(4) False. Magnitude of charge on any radical is its valency. 

(5) True 

(6) False. The proportion by weight of carbon and oxygen in carbon dioxide is 3 : 8. 

(7) True 

(8) False. The number of molecules in a given quantity of a substance is determined by its molecular mass. 

(9) True 

(10) False. Valency of sodium is 1.

B) In presence of water, Cl₂ gives nascent oxygen. 

The range of Balmer series is 656.3 nm to 365 nm. It can resolve λ and λ + Δλ if  λ/Δλ = 8000.

No.of wavelengths in the range =656.3-365/8000=36

Total no.of lines 36 + 2 = 38 [extra two is for first and last wavelength]

Anti-oxidants.

K₂Cr₂O₇/H₂SO₄, KMnO₄/H₂SO₄ are the commonly used chemical oxidants. Hydrogen peroxide (H₂O₂) is used as a mild oxidant. Ozone (O₃) is also a chemical oxidant. Nascent oxygen is generated by chemical oxidants and it is used for the oxidation reaction.

O₃ → O₂ + [O].

H₂O₂ → H₂O + [O]

K₂Cr₂O₇ + 4H₂SO₄ → K₂SO₄ + Cr₂(SO₄)₃ + 4H₂O + 3[O]

2KMnO₄ + 3H₂SO₄ → K₂SO₄ + 2MnSO₄ + 3H₂O + 5[O]

Nascent oxygen is a state prior to the formation of the O₂ molecule. It is the reactive form of oxygen and is represented by the symbol as [O]

Oxidants: SO₂, MnO₂

Reductants: H₂S, HCl

i. Rancidity: The oxidation of oils and fats in foods resulting into a bad smell and bad taste is called rancidity.
ii. To prevent rancidity, substances called ‘antioxidants’ are added to food (that contains fats and oils.)
iii. Rancidity can also be prevented: 

a. By flushing packets of food items like chips with nitrogen.

b. By storing the food inairtight container to slow down the process of oxidation.

BHA (Butylated Hydroxy Anisole) and BHT (Butylated Hydroxy Toluene). 

Anti-oxidant is a substance which prevents oxidation. They are added to fat and oil containing foods so that they do not get oxidized easily and hence do not turn rancid.

The wounded man was the enemy of the kMg. He wanted to kill the king but the king saved his life. The wounded man asked the kings forgiveness and wanted to serve the king as a very faithful slave.

The three questions for which the king wanted to have answers were: 

1. What is the right time to begin something? 

2. Who should a king consider the most important? 

3. What is the most important thing for a king to do.

The king was so tired from his walk, from the digging work with the spade and from putting all his effort to save the bearded man. So he slept soundly through the night.

The king was advised to go to the magicians in order to know the right time for every action.

No, the King was not satisfied with the answers, because they were different in opinions of the wise men.

The king and the hermit unfastened the man’s clothing. The king washed the wound in his stomach and bandaged it with his handkerchief and with a towel the hermit had. When the blood stopped flowing, the king gave fresh water for him to drink. Then the king, with the hermit’s help, carried the wounded man into the hut and laid him on the bed.

Correct answer is (a) hermit

4. The king proclaimed throughout his kingdom to give reward for the correct answers to his questions.

2. The learned men answered the kings questions differently. 

5. The king agreed with none of the learned men and gave the reward to none. 

1. King decided to consult a hermit known for his wisdom. 

3. The king put on simple clothes and went alone to the hermit’s cell.

1. True 

2. False 

3. False 

4. True 

5. False

No, the king was not satisfied with the answers. Because all the answers were different and the king could not agree with none of them.

The bearded man was wounded in his stomach.

1. True 

2. False 

3. True 

4. True

1. magicians

2. wisdom 

3. common folk

4. digging

Correct answer is (a) three

A medicine can bind to more than one receptor site, thus a medicine may be toxic for some receptor site Further, in most cases, medicines cause harmful effects when taken in higher dose than recommended As a result, medicines may be poisonous in such cases Hence, medicines should not be taken without consulting doctors.

1. unfastened 

2. handkerchief 

3. slave 

4. Physician

1. effect 

2. lie 

3. rise 

4. advice 

5. effect

Correct answer is (c) peace

Carbohydrates, lipids, proteins and nucleic acids are the macromolecules selected as targets for the drugs.

Carbohydrates, lipids, proteins, Nucleic acids 

(i) He may get head injury that may even prove fatal to him.
(ii) Brain, Eye.
(iii) Obeying traffic rules while travelling on the roads, be careful while driving, obeying instructions by elders.

Correct answer is (a) wood

Proteins, carbohydrates, lipids and nucleic acids.

Target molecules or drug targets are the macro molecules such as carbohydrates, proteins, lipids, noucleic acids with which the drug interacts in our body to produce therapeutic effect.

(a) Lead sulphate is prepared from insoluble lead oxide, by first converting lead oxide into soluble lead nitrate with dilute nitric acid and then treating the resulting solution with sulphuric acid to obtain white ppt. of Lead sulphate.

PbO + 2HNO₃ ⟶ Pb(NO₃)₂ + H₂O

Pb(NO₃)₂ + H₂SO₄ ⟶ PbSO₄ + 2HNO₃

(b) Lead sulfate is insoluble, when lead is added to sulfuric acid it only reacts on the surface. The lead becomes coated with insoluble lead sulfate and the lead in the interior can't react. Therefore lead sulfate cannot be prepared by adding dilute sulfuric acid.

4NaCl+MnO₂+4H₂SO₄ → MnCl₂ + 4NaHSO₄ +Cl₂ +H₂O

The state of hybridization of B in sp³.