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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 301. |
Why are microwaves considered suitable for radar system used in aircraft navigation? |
| Answer» Microwaves pass straight through the atmosphere without any deviation. | |
| 302. |
Name the part of electromagnetic spectrum which is suitable for (i) radar system used in aircraft navigation (ii) treatment of cancer tumours. |
| Answer» (i) Microwave (ii) Gamma rays | |
| 303. |
Differentiate between the molecular structures and behaviour of thermoplastic and thermosetting polymers. Give one example of each type |
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Answer» (i) Thermoplastic polymers : These are polymers which can be moulding on heating. These polymers posseers intermolecular forces of attraction intermediate between elastomers and fibres. e.g Polythene. Thermosetting polymers : These are low molecular mass semifluid polymer,which on heating form infusible hard mass and cannot be remoulded. e.g. Bakelite. |
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| 304. |
Explain the following terms with one suitable example in each case. (i) Cationic detregents (ii) Enzymes (iii) Antifertility drugs |
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Answer» (i) Cationic detergents : Cationic detergents are quarternary ammonium salts of amines with acetates, chlorides, or bromides as anions. Example : Cetyltrimethyl ammonium bromide. (ii) Enzymes : Enzymes are the biological catalysts which increase the rate of metabolism. Example : Zymase (iii) Antifertility drugs : Drugs which are used to control birth rate. Example : Norethindrone,Novestrol. |
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| 305. |
(a) Following are the transition metal ions of 3d series: `Ti^(4+),V^(2+),Mn^(3+),Cr^(3+)` (Atomic numbers: `Ti=22,V=23,Mn=25,Cr=24`) Answer the following: (i) Which ion is most stable in an aqueous solution and why? (ii) Which ion is a strong oxidising agent and why? (iii) Which ion is colourless and why? (b) Complete the following equations: (i) `2MnO_(4)^(-)+16H^(+)+5S^(-)to` (ii) `KMnO_(4)overset(heat)to` |
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Answer» (a) `Ti^(4+)=3d^(@),V^(2+)=3d^(3),Mn^(3+)=3d^(4),Cr^(3+)=3d^(3)` Out of these four ions,`Cr^(3+)` is most stable due to crystal field splitting concept. In `Cr^(3+),t_(2)g` in half-filled. Hence, is extra stable. (ii) `Mn^(3+)` is strong oxidising agent because `Mn^(3+)` can easily be converted into `Mn^(2+)` having `d^(5)` configuration which is stable half-filled configuration. ltBrgt (iii) `Ti^(4+)` is colourless because it is having no unpaired `e^(-)` for excitation to higher energy level and it is colourless. (b) (i) `2MnO_(4)^(-)+16H^(+)+5S^(2)to2Mn^(2+)+8H_(2)O+5S` (ii) `2KMnO_(4)overset(Delta)tounderset(("Pot. manganate"))(K_(2)MnO_(4)+MnO_(2))+O_(2)` |
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| 306. |
(a) An iron ring of relative permeability `mu_(r)` has windings of insulated copper wire of n turns per metre. When the current in the windings is I, find the expression for the magnetic field in the ring. (b) The susceptibility of a magnetic material is 0.9853. Identify the type of magnetic material. Draw the modification of the field pattern on keeping a piece of this material in a uniform magnetic field. |
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Answer» (a) Given relative permeability = `mu`, Then permeability of iron `= mu _(0) mu` Number of turns per meter = n Current = I Now `Deltat` center of salenoid cut an element of thickness dx at x meter from its centres So, number of turns in dx element is. `N = ndx` Now else, Bio Savart Law `B = (mu_(0)muNiR^(2))/((R^(2) + n^(2))^(3//2))` let, K is the radius of circular path `= (mu_(0)mu_(i)dxR^(2))/((R^(2) + n^(2))^(3//2))` After integration. (b) (i) As we know that suscecptibility of a paramagnetic substances is positive (+ ve) though small. Here the given magnetic material is paramagnetic in nature. (ii) When a.specimen of a paramegnetic substance is placed in a magnetic field, the magnetic field line prefer to pass through air thus, magnetic induction B inside the sample is more than the magnetic induction `B_(0)` outside the sample. |
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| 307. |
In fig. `C_(1) = 20 muF, C_(2) = 30 muF and C_(3) = 15 muF` and the insulated plate of `C_(1)` is at a potential of 90 V, one plate of `C_(3)` being earthed. What is the potential difference between th plates of `C_(2)` three capacitors being connected in series ? |
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Answer» we given `C_(1)=20muF, C_(2)=30 muF, C_(3)=15 muF,V=90V` `1/C=1/C_(1)+1/C_(2)+1/C_(3)Rightarrow1/C = 1/20 +1/30 +1/15 = ( 3+2+4)/60 = 9/60 = 3/20 Rightarrow 1/C = 3/20 C=20/3 = 6.6 muF` When the capaciter connected in series, charge on each capacitor is same. Let q be the charge on each capacitor, if ` V_(1),V_(2) and V_(3)` are potential difference across these, capacitors. ` V_(1)+V_(2) +V_(3) = 90` `or q/(20xx10^(-6)) +q/(30xx10^(-6))+q/(15xx10^(-6)) =90, (3q +2q +4q)/(60xx 10^(-6)) =90, (9q)/(60 xx 10^(-6)) = 90` `q=(overset(10)cancel(90))/cancel(9)xx60 xx10^(-6)= 600xx10^(-6)= 6.0 xx 10^(-4)C` Energy stored, `U=1/2CV^(2)=1/(cancel(2))xxoverset(3.0)cancel6.0xx10^(-4)xx30xx30=27000 xx 10^(-4) = 2.7` J |
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| 308. |
Find the value of phase lag/lead between the current and voltage in the given CLR circuit, fig. Without making any other change, find the value of additional capacitor, such that when joined switably to `C = 2 mu F`, would make the power factor of this circuit unity. |
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Answer» (a) ` V=V_(0) sin (1000 t + phi)` ` V=V_(0) sin ( omegat+ phi) ` `omega=1000` ` X_(L) = omegaL` ` X_(L) = 1000 xx 100 xx10^(-3) =10^(2) = 1000 Omega` `X_(C) = 1/(omegaC) = 1/(1000 xx 2xx 10^(-6)) =1/2 xx 10^(3) = 500 Omega` Phase difference ` tan phi= ( X_(L) -X_(C))/R` ` tan phi = (X_(C)-X_(L))/R ,X_(C) gt X_(L)` ` tan phi = (500 -100)/400 = 400/400 =1` ` tan phi =1` ` tan phi tan 45^(@)` `phi = 45` Now ` sqrt(R^(2) +(X_(L) -X_(C))^(2))` ` = sqrt(400^(@)(100-500)^(2)) = sqrt(160000 + 160000) = sqrt(320000) = 565.68` power factor = ` cos phi R/Z= 400/565.68 = 0.707` (b) ` X_(L)=X_(C) . " Let new , capatior " = C_(1)` ` omegaL= 1/(omegaC)` `C= = 1/(omega^(2)L) =1/(2pif)^(2) X_(L)) = 1/(4pi^(2)f^(2)L)` ` 2xx 1-^(-6) +C_(1) = 1/( 4xx (3.14)^(2) xx (50)^(2) xx 100 xx 10^(-3)) = 1/( 4xx 9.8596 xx 2500 xx 10^(-1))` ` 1/(4xx 9.8596 xx250) = 1/(9859.6)` ` C_(1) =1/(9859.6) -2 xx 10^(-6) = 1/(9859.6) -2/10^(6) = 0.000101424-0.000002= 0.00009924=99.42 muF` |
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| 309. |
Write an alternate source of protein for animal and human nutrition. |
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Answer» The alternate source of protein for animal and human nutrition is single cell protein. Eg. Spiriulina. |
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| 310. |
Identify the type of the given ecological pyramid and give one example each of pyramid of number and pyramid of biomass in such cases. |
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Answer» Pyramid of biomass Small standing crop of Phytoplankton support large standing crop of Zooplankton The given ecological Pyramid is the inverted pyramid of biomass in a lake : phytoplankton `rarr` zooplankton `rarr` fishes. Pyramid of numbers: Tree `rarr` Insect `rarr` Birds. |
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| 311. |
Explain any three contraceptive devices that can be used by women for their family planning. |
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Answer» The following are the three contraceptive devices that can be used by women for family planning : (i) Barrier methods : This includes condom for females that covers the vagina and cervix. (ii) Intrauterine devices : (IUDS) : These are inserted by docters or expert nurses in the uterus or vagina. For example : Lippes loop, cut and multilood 375. (iii) Pills : These include progestogen pills or progestogen-estrogen combination pills. |
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| 312. |
Explain polygenic ingeritance with the help of a suitable example. |
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Answer» The process of evolution that a single point and radiates in different directions are called adaptive radiation. Australian marsupial has evolved from a single ancestor and placental mammals exhibit. similarities with their corresponding marsupial, such as placental wolves and Tasmanian wolves. |
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| 313. |
(a) How are Mendelian inheritance, polygenic inheritance arid pleiotropy different from each other ? (b) Explain polygenic inheritance pattern with the help of a suitable example. |
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Answer» Pleiotropy-A single gene that has an effect on the expression of two or more phenotypic traits is said to have a pleiotropic effect- on the traits. For example, testosterone controls the development of what are referredto as secondary sexual characteristics, but testosterone also relates to behavioral traits like aggression. Thus, a gene that controls the level of testosterone would have a pleiotropic effect on the expression of many secondary sexual traits which are morphological, as well as behavioral 2. Polygenic Iftwo or more genes are responsible for a single trait, the phenotypic trait is said to be governed by polygenic factors. For example, growth rate is undoubtedly caused by a number of genes that act in a complex cascade. 3. Mendelian inheritcance : It states the following : (a) Law of Dominance (i) Characters are controlled by discrete units called factors. (ii) Factors occur in pairs. (iii) In a dissimilar pair of factors one member of the pair dominates (dominant) the other (recessive). (b) Law of segregation:Aeles do not show any blending and both the charactors are recovered in `F_2` generation though one of these is not seen at the `F_1` stage. (c) Law of independent assortment: When two pairs of traits are combined in a hyhrid, segregation of one pair of characters is independent of the other pair of characters. (b) See point 2., Polygenic inheritance [above]. . |
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| 314. |
Give an example of a polygenic trait in humans. |
| Answer» An example of a polygenic trait is skin colour. | |
| 315. |
Name the male accenssory glands in human and write their functions. |
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Answer» The male accessory glands include paired seminal vesicles, a prostate and paired bulbourethral glands. Secretion of these glands consititute the seminal plasma which is rich in the fructose, calcium and certain enzymes. The secretions of bulbourethral glands also helps in the lubrication of the penis. |
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| 316. |
(a) Explain why `H_(2)and O_(2)` do not react at room temperature. (b) Writen the rate equation for the reaction `A_(2)+3B_(2)to 2C,` if the overall order of the reaction is zero. |
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Answer» (a) `H_(2)and O_(2)` do not react at room temperature because the activation energy is high for that reaction which is not provided at room temperature. (b) For zero order reaction : `" "Rate=k[A_(2)]^(@)[B_(2)]^(@)` |
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| 317. |
Name the junction diode whose I-V characteristics are drawn below: |
| Answer» Correct Answer - Photo Diode. | |
| 318. |
How is the speed of EM waves in vacuum determined by the electric and magnetic fields ? |
| Answer» Speed of em-waves is given `C = E_(0)//B_(0)`. | |
| 319. |
What is differnece between an emulsion and a gel ? |
| Answer» Emulsion is a colloidal solution in which both the dispersed phase and dispersion medium are liquids. Where gel is a colloidal solution in which dispersed phase are liquids but dispersion medium are solids | |
| 320. |
Complete the following reaction equations : (i) `C_(6)H_(5)N_(2)Cl+CH_(3)COCl to` (ii) `C_(2)H_(5)NH_(2)+C_(6)SO_(2)Cl to` (iii) `C_(2)H_(5)NH_(2)+HNO_(2)to` |
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Answer» `C_(6)H_(5)N_(2)Cl+CH_(3)COCl to C_(6)H_(5)NH_(2)COCH_(3)Cl tounderset("N- Benzalamide")(C_(6)H_(5)NHCOCH_(3)+HCl)` (ii) `C_(2)H_(5)NH_(2)+C_(6)H_(5)SO_(2)Cl to C_(6)H_(5)SO_(2)NHC_(2)H_(5)` (iii) `C_(2)H_(5)NH_(2)+HNO_(2)overset(NaNO_(2)+HCl)to[C_(2)H_(5)N_(2)^(+)Cl^(-)]overset(H_(2)O)toC_(2)H_(5)OH+N_(2)+HCl` |
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| 321. |
Define associated colloid with an example. |
| Answer» Some substance at higher concentration exhibits colloidal behavior due to the formation of aggergates.The aggregated particles thus formed are called micelles or associated colloids. | |
| 322. |
Why is t- butyl bromide more reactive towards `S_N 1` reaction as compared to n- butyl bromide? |
| Answer» A tertiary alkyl tends to undergo the `S_N1` mechanism because it can form a tertiary carbocation which is stabilized by the three alkyl group attached to it . As alkyl group are electron donating . They allowed the positve charge in the carbocation to be delocalised by the induction effect.Hence out of given pair `(CH_3)_3 CBr` would undergo `S_N1`reaction faster. | |
| 323. |
Complete the following reactions: `(i) PbS(s)+O_3rarr` (ii) `XeF_6+NaF rarr` ( b) Arrange the following in increasing order of property indicated ,given reason: (i) Hydeides of group 15-boiling points ( ii) Hydrides of group 17 - acidic strength (iii) Hydrides of group 16-reducing charcter. |
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Answer» ( a) `Pbs(s) O_3 rarr PbSO_4+O_2` (ii)`XeF_6+NaF rarr Na+XeF_7` ( b) See Q.29 (or) (b) (i) Paper - 2014 ( C) Delhi Board ,Set-I[page 263] (ii)`HF lt HCl lt HBr` Hi the size of halogens is incresing sdown the group so due to a large size difference between halogen and hydrogen , the compound can easily loose proton and this character of loosing proton depicts its acidity. |
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| 324. |
A first order reaction takes 20 minutes for 25% decomposition. Calculate the time when 75% of the reaction will be completed. (Given, `log2=0.3010,log3=0.4771,log4=0.6021`) |
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Answer» `t_(25%)=20` min `k=(2.303)/(t)log((a)/(a-x))" "[{:(ato"Initial conc."),(xto" reacted"),(a-xto" remaining"):}]` `k=(2.303)/(20)log((cancel(100))/(cancel(75)))["Div. by"25]` `k=(2.303)/(20)(log4-log3)` `implies(2.303)/(20)xx(0.6021-0.4771)` `impliesk=(2.303)/(20)xx0.125s^(-1)` `t_(75%)=(2.303)/(k)log((cancel(100))/(cancel(25)))` `=(2.303xx20)/(2.303xx0.125)xx0.6021=t_(75%)=96.34sec`. |
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| 325. |
Define each of the following : (i) Specific rate of a reaction. (ii) Energy of activition of a reaction |
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Answer» (i) A given temperature , rate is equal to the rate constant of reaction when concentration of the reactant in unity. Thus rate constant is also known as specific reaction rate. In the case of two reactants, the raction may be written as : `" "A + Bto` Products `" "r=(dx)/(dt)=kC_(A)C_(B)` Where all the terms have usual meaning. If `C_(A)=C_(B)=1` then `r=k` (ii) Activation energy, in chemistry , the minimum amount of energy that is required to activate atoms or molecules to a condition in which they can undergo chemical transformation of physical transport . In term of the transition-state theory, the activating energy is the difference in energy content between atoms or molecules in an activated or transitionstate configuration and the corresponding atoms and molecules in their initial configuration . The activation energy is usually respected by the symbol `E_(a)` in mathematical expressions for such quantities as the reaction-rate constant , k=Aexp`(-E_(a)RT)`. |
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| 326. |
Why is nitrogen gas very unreactive ? |
| Answer» Nitrogen gas is formed whe the nitrogen atoms bond together thus resulting in a triple bond between the nitrogen atoms these triple bond together have a very high bond enthalpy (energy needed to break bonds). So the energy needed to break the bonds is very high. Since chemical reactions occur on the basis that bond need to be broken for new bonds to form . The nitrogen molecules does not react readily under normal circumstances. | |
| 327. |
What is the role of `CO_(2)` in the extractive metallurgy of aluminium from its ore ? |
| Answer» The solution which now contains the oxides of aluminum and silicon are next treated by bubbling carbon dioxide gas through the solution . Carbon dioxide forms a weak acid solution of carbonic acid which neutralizes the sodium hydroxide from the first treatment . This neutralization selectively precipitates the aluminum oxide, but leaves the silicates in solution. Again filtration is used for the separation . After this stage the the purified aluminum oxide is heated to evaporate the water. | |
| 328. |
A first order decomposition reaction takes 40 minutes for 30% decomposition. Calculate its `t_(1//2)` value. |
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Answer» Here t = 400 min., `t_(1//2)=?` Let a = 100 `therefore` x = 30% of 100 = 30 using the formula, `{:(t=(2.303)/(K)log.(a)/(a-x),|,rArr,40=(2.302)/(K)log.(100)/(100-30)),(40=(2.303)/(K)log.(100)/(70),rArr,40=(2.303)/(K)(log10-log7),),(40=(2.303)/(K)(1-0.8451),rArr,40=(2.303)/(K)xx0.1549,),(K=(2.303xx0.1549)/(40),rArr,K=(0.357)/(40)=0.0089" min",):}` `therefore t_(1//2)=(0.693)/(K)=(0.693)/(0.0089)=77.86` min. |
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| 329. |
(a) Define self inductance. Write its S.I. units (b) Derive and expression for self inductance of a long solenoid of length l cross-sectional area A having N number of turns. |
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Answer» (a) Self Inductance (or co-efficient of self induction) : Self inductance of a coil is numerically equal to the amount of magnetic flux linked with the coil when unit current flows through the coil. Its S.I. units is Henry (H) (b) Self Inductance of a Long solenoid. Consider a long solenoid of length l, number of turns N and radius r. Suppose current I flows through it. Magnetic field set up in the coil is `B = (mu_(0)NI)/(l)` Flux through each turn `= BA = (mu_(0)NIA)/(l)` Total flux through N turns, `phi = N xx (mu_(0)NIA)/(l) = (mu_(0)N^(2)IA)/(l) " But " phi = LI` `:.` Self inductance, `L = (phi)/(I) = (mu_(0)N^(2)A)/(l)` |
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| 330. |
Suggest a method to ensure an anamnetic response in humans. |
| Answer» During vaccination, inactivated or weakened pathogen introduced in the body. The antibodies produced against these antigens would neutralize the pathogen agents. This is a method to ensure an anamnestic response in human. | |
| 331. |
State the fate of a pair of autosomes during gamete formation. |
| Answer» Humans have 22 pairs of autosomes. It also redcues in number during meiotic division of gamete but remains same in both gametes. | |
| 332. |
Our government has intentionally imposed strict conditions for M.T.P. In our country. Justify giving a reason. |
| Answer» M.T.P (Medical Termination of Pregnancy)- Nearly 45 to 50 million MTPs are performed in a year all over the world for which, Government of India legalized MTP in 1971 with some strict conditions to avoid its misues. It Is more important to restrict on indiscrimination and illegal female foeticides, which are reported to be high in India. | |
| 333. |
Explain the two factors responsible for conferring stability to double hilix structure of DNA. |
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Answer» Factors responsible for conferring stability to helix xtructure of DNA. (i) Presence of hydrogen bond in between base pair stacks confers stability to DNA. (ii) Presence of thymine at the place of uracil gives more stability to DNA. |
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| 334. |
Write the effect of the high concentration of L.H. on a mature Graafian follicle. |
| Answer» LH attains a peak level in the middle of cycle (about `14^(th)` day ). This LH surge induces repture of Graafian follicle and release of ovum leading to ovulation. | |
| 335. |
(a) Explain adaptive radiation with the help of a suitable example. (b) City an example where more than one adaptive radiations have occurred in an isolated geographical area. Name the type evolution your example depicts and state why it is so named. |
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Answer» (a) Darwin finches/black birds (on Galapagos islands), evolved from origin seed eating features, into insectivorous & vegetarian finches in different parts of island. (b) (i) Australian marsupials each different from the other evolved from a common ancestor but within the Australian continent. Placental mammals in Australia show adaptive radiation and appear similar to Australian marsupials. (ii) Convergent evolution, more than one adaptive ratidation occured in isolated geographical area. |
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| 336. |
An electron is accelerated through a potential difference V. Write the expression for its final speed , if it was initially at rest. |
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Answer» According to work energy theorem , work done is equal to change in kinetic energy. So , `{:(W=K_(f)-K_("i"),,W=(1)/(2)mv^(2)-(1)/(2)m u^(2)),(V=(W)/(q)=(W)/(e),rArr,W=eVandu=0),(eV=(1)/(2)mv^(2),,v^(2)=(2eV)/(m)),(v=sqrt((2eV)/(m)),,):}` |
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| 337. |
Why is it not possible for an alien DNA to become part of a chromosome anywhere along its length and replicate normally ? |
| Answer» This is because in a chromosome there is a specific DNA sequence called the origin of replication which is responsible for initiating replication. The alien DNA has to be linked to this origin of replication for it to multiply in the gost organism. | |
| 338. |
Mention the type of host cells suitable for the gene guns to introduce an alien DNA. |
| Answer» Undifferentiated plant cells are the most suitable host cells for the gene guns to introduce an allien DNA. It is because plant cells have rigid cell wall which can be easily broken down by bombarding them with high velocity micro-particles of gold or tungsten coated with DNA in a gene gun. | |
| 339. |
Write the function of a Bioreactor. |
| Answer» Bioreactors can be thought of as vessels in which raw materials are biologically converted into specific products, individual enzymes etc., microbial plant, animal or human cell. | |
| 340. |
A colour blind boy is born to a couple with a normal colour vision. Write the genotype of the parents. |
| Answer» `{:("Father" ," Mother ", N = "Normal vision"),(X^(N) Y^(N), " " X^(C) X^(+),C = "Carrier"),(,, += "dominant"):} ` | |
| 341. |
Name and explain the role of inner and middle walls of the human uterus. |
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Answer» The inner glandular wall of the uterus is known as endometrium. Role (i) During the menstrual cycle, the endometrium wall grows into a thick, blood vessel-rich, glandular laye. This condition of the endomentrium favors the implantation of the foetus.If fertilisation does not occur, the endometrum is sehd during hemorrhagic phase of the menstrual cycle. ii) The middle wall of the uterus is known as myometrium. It consists of smooth muscles. It brings about contraction while delivery of the baby. |
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| 342. |
A color-blind child is born to a normal couple. Work out a cross to show how it is possible. Mention the sex of this child. |
| Answer» `{:(, " Male" ,,,,"female ",),(,XY,,,,X^( c)X),( X,,Y,,X^( c) ,,x),( ,,X^( c)X,,XX,,XY),( ,,"Carrierfemale ",,"normal ",,Normal "),( ,,,,"female ",,"male"),(,,,X^( c) Y,,,),(,,,"Color blind male",,,):}` | |
| 343. |
In the figure given, mark the polarity of plates A and B of a capacitor when the magnets are quickly moved towards the coil. |
| Answer» In this situation A will become positive reference to B as the current induced is in clockwise direction | |
| 344. |
(a) What is the covalence of nitrogen in `N_(2)O_(5)`? (b) `BiH_(3)` is stronger reducing agent than `SbH_(3)`, why ? |
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Answer» (a) Covalency of nitrogen is `N_(2)O_(5)` is 4. (b) As we move down the group, the size of element increases, the length of E-H bond increases and its strength decreases and can break more easily to evolve `H_(2)` gas which acts as reducing agent. The Bi-H bond is weaker than Sb-H. Hence, `BiH_(3)` is strong reducing agent than `SbH_(3)`. |
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| 345. |
What is the covalence of nitrogen in `N_2O_5`? |
| Answer» The covalency of nitrogen in `N_2O_5` is 4. | |
| 346. |
Why is Tyndall effect shown by colloidal solutions ? |
| Answer» Tyndall effect is shown by colloidal solution because the size of particles is such `(10A^(@)-10000A^(@))` that they can scatter light. | |
| 347. |
If the half-life period of a first order reaction in A is 2 minutes, how long will it take [A] to reach `25%` of its initial concentration ? |
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Answer» `t1//2=2min." "rArr" "t1//2=(0.693)/(K)" "rArr" "K=(0.693)/(2)=0.3465"min"^(-1)` For `1^(st)` order reaction : `K=(2.303)/(t)log.(a)/(a-x)" "ararr"initail concentration"` `xrarr"reacted"` `a-xrarr"remaining"` `t=(2.303)/(0.3465)log.(cancel100^(4))/(cancel25_(1))" "rArr" "t=6.646xx2log2=6.46xx2xx0.3010` `t = 4.00"mins".` |
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| 348. |
A mixed oxide of iron and chromium is fused with sodium carbonate in free access of air to from a yellow, coloured compound (A). On acidification the compounf (A) froms an orange coloured compound (B), which is a strong oxidizing agent. Identify compound (A) and (B). Write chemical reactions involved. |
| Answer» `underset(("ore"))underset("Chromite")(4FeO. Cr_(2))O_(3)+underset("Carbonate")underset("Sodium")(8Na_(2))CO_(3)+7Oto underset(("Yellow"))underset((A))underset("Sodium Chromate")(8Na_(2)CrO_(4)+2Fe_(2))O_(3)+8CO_(2)` | |
| 349. |
For the complex `[Fe (en)_2Cl_2]Cl`, identify the following: (i) Oxidation number of iron. (ii) Hybrid orbitals and shape of the complex. (iii) Magnetic behaviour of the complex. (iv) Number of its geometrical isomers. (v) whether there may be optical isomer also. |
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Answer» (i) Given complex is `[Fw(en)_2Cl_2]Cl` `x+(0) +2(-1)+(-1)=0` `rArr x-3=0 :. X=3` oxidation number of Fe = 3 (ii) Hybridisation `: d^2sp^3` Shape of complex : octehedral (iii) paramagnetic (iv) two (v) Yes |
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| 350. |
Name the bases present in RNA. Which one these is not present in DNA ? |
| Answer» Bases present in RNA are adenine, guanine, cytosine and uracil. Uracil is not present in DNA. Instead of uracil, thymine is present in DNA. | |