This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
If each term in an equation has same base units then the equation is said to beA. homogeneousB. non homogeneousC. equation of straight lineD. equation of circle |
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Answer» A. homogeneous |
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| 2. |
An object immersed in fluid experiences an upward force namedA. viscosityB. drag forceC. up thrustD. friction |
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Answer» C. up thrust |
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| 3. |
Prefix for 10-9 isA. microB. deciC. centiD. nano |
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Answer» The Correct option is D. nano |
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| 4. |
Force which makes it difficult to run through shallow water is calledA. viscosityB. up thrustC. frictionD. drag |
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Answer» The Correct option is D. drag |
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| 5. |
The larger the mass of a moving object theA. larger the acceleration producedB. acceleration becomes constantC. smaller the accelerationD. acceleration becomes zero |
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Answer» C. smaller the acceleration |
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| 6. |
A curve is plotted to represenet the dependence of the ratio of the received frequency `f` to the frequency `f_0` emitted by the source on the ratio of the speed of obsever `V_(ob)` to the speed of sound `V_(sound)` in a situation in which an observer is moving towards a stationary sound source. The curve is best represnted by :A. B. C. D. |
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Answer» `f=f_0(1+V_(ob)/V_(sound))` `rArr f/f_0=1+V_(ob)/V_(sound)`(straight line) , when `V_(ob)/V_(sound)=0 ,f/(f_(0))=1` and as `V_(ob)/V_(sound)to 1 rArr f/(f_(0)) to 2` |
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| 7. |
If the potential difference applied across a Coolidge tube is increased , thenA. `lambda_("min")` will decreases.B. characterstic wavelength will increasesC. `lambda_("min")` will increases.D. none of these |
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Answer» `lambda_("min")=(hc)/(eV)` `lambda_("min") prop 1/V` As `lambda_("min")` decreases. V increases. So choice (a) is correct and the rest are wrong. |
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| 8. |
Define phase margin (PM) |
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Answer» Phase margin is that amount of additional phase lag at the gain crossover frequency required to bring the system to the verge of instability. |
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| 9. |
Difference between gain crossover frequency and phase crossover frequency ? |
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Answer» Gain Crossover Frequency: Gain crossover frequency is that frequency at which, [G(jω)], the magnitude of the open loop transfer function is unity. The Phase margin PM is 180° plus the phase angle φ of the open loop transfer function at the gain crossover frequency. PM = (180°(+φ)at GCF) Phase Crossover Frequency: Phase crossover frequency is that frequency at which, ∠G(jω), the phase angle of the open loop transfer function equals ‐180°. Thus, Gain Margin, GM = (1/jG(jω))at PCF In terms of decibels, GM dB = 20 logIG(jω))at PCF |
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| 10. |
a) Give one point of difference between nuclear fission and nuclear fusion. b) Suppose we consider fission of a 5626Fe into two equal fragments of 2813Al nucleus. Is the fission energetically possible? Justify your answer by working out Q value of the process. Given (m)5626Fe = 55.93494 u and (m)2813Al = 27.98191 |
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Answer» (a) Fusion takes place when two low-mass isotopes, typically isotopes of hydrogen, unite under conditions of extreme pressure and temperature whereas fission is the splitting of a heavy, unstable nucleus into two lighter nuclei. (b) \(^{56}_{26}Fe\) → 2 \(^{28}_{13}Al\) Q = Δm x 931 Mev = \(\big(\)m[\(^{56}_{26}Fe\)] - 2m[ \(^{28}_{13}Al\)]\(\big)\) x 931 Mev = (55.93494 - 2 x 27.98191) x 931 Mev = -0.02886 x 931 Mev = -26.88 Mev < 0 The fission is not possible energetically. One difference between nuclear fission and nuclear fusion Calculating Q=((m) Fe-2(m) Al)C2 =26.90MeV Justification not possible |
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| 11. |
Define ‘Electric field’. |
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Answer» The electric field at the point P at a distance r from the point charge q is the force experienced by a unit charge and is given by \(\vec E\) = \(\frac{\vec F}{q_0}\) The electric field is a vector quantity and its Sl unit is Newton per Coulomb (NC-1). |
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| 12. |
State the principle of potentiometer. |
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Answer» The basic principle of a potentiometer is that when a constant current flows through a wire of uniform cross-sectional area and composition, the potential drop across any length of the wire is directly proportional to that length. |
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| 13. |
If the focal length is 150 cm for a glass lens, what is the power of the lens? |
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Answer» Given: focal length,f = 150 cm (or) f= 1.5 m Equation for power of lens is, P = 1/f Substituting the values, P = \(\frac{1}{1.5}\) 0.067 diopter As the power is positive, it is a converging lens. |
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| 14. |
6C3 |
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Answer» 6C3=\(\frac{6!}{3!3!}=\frac{6\times5\times4\times3!}{3!\times3!}\) \(\frac{120}{6}=20\) |
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| 15. |
Explain the need for a feedback circuit in a transistor oscillator. |
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Answer» The circuit used to feedback a portion of the output to the input is called the feedback network. If the portion of the output fed to the input is in phase with the input, then the magnitude of the input signal increases. It is necessary for sustained oscillations. |
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| 16. |
Size of C.S windows is ___________(a) 5″*6″(b) 4’*2′(c) 4’*2.5′(d) 11″*3’5″ |
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Answer» The correct answer is (b) 4’*2′ Best explanation: A casement window is a window with a hinged sash that swings in or out like a door comprising either a side-hung, top-hung (also called “awning window”; see below), or occasionally bottom-hung sash or a combination of these types, sometimes with fixed panels on one or more sides of the sash. In the USA, these are usually opened using a crank, but in parts of Europe they tend to use projection friction stays and espagnolette locking. Formerly, plain hinges were used with a casement stay. Handing applies to casement windows to determine direction of swing; a casement window may be left-handed, right-handed, or double. The casement window is the dominant type now found in modern buildings in the UK and many other parts of Europe. |
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| 17. |
If each diode in Fig. 14.13 has a forward bias resistance of 25Ω and infinite resistance in reverse bias, what will be the values of the current I1, I2, I3 and I4? |
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Answer» I3 is zero as the diode in that branch is reverse bised. Resistance in the branch AB and EF are each (125 + 25)Ω = 150Ω. As AB and EF are identical parallel branches, their effective resistance is 150/2=75Ω Net resistance in the circuit = (75 + 25) Ω = 100Ω . Current I1=5/100=0.05A. As resistances of AB and EF are equal, and I1 = I2 + I3 + I4, I3 = 0 I2=I4=0.05/2=0.025A |
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| 18. |
Enzymes speed up the reaction uptoa) 10¹⁰ timesb) 10²⁰ timesc) 10¹⁰⁰ timesd) 10 times |
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Answer» Enzymes are biological catalyst they decrease the activation energy of reaction and speed up the rate of reaction. they increases the rate of biological reaction upto 107 to 1020 times. |
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| 19. |
The melting point of camphor is 177.5 degree Celsius while that of a mixture of one gram naphthalene and 10 gram of camphor is 147 degree Celsius, calculate the cryoscopy constant of camphor. |
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Answer» Cryoscopic constant is the depression of the freezing point of the solvent produced on dissolving are mole of substance in 1000g of it. it is also called molal depression constant. it is denoted by Kf. As we know, depression in freezing point △Tf = Kf m where, m = molality Kf = Cryoscopic constant △Tf = depression in freezing point we have given △Tf = 177.5 - 147 = 30.5 °C Number of moles of Naphthalene = \(\frac1{128}\) mole molality = \(\cfrac{\frac1{128}}{10}\times1000\) = 0.78 m Therefore, Kf = \(\frac{30.5}{0.78}\) Kf = 39.1 °C kg mol-1 Hence, the cryosopic constant will be 39.1 °C kg mol-1 |
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| 20. |
Vapour absorption refrigeration system works using the (a) ability of a substance to get easily condensed or evaporated (b) ability of a vapour to get compressed or expanded (c) affinity of a substance for another substance (d) absorptivity of a substance. |
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Answer» (c) affinity of a substance for another substance |
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| 21. |
To fix the state point in respect of air-vapour mixtures, three intrinsic properties are needed. Yet, the psychrometric chart requires only two because (a) water vapour is in the superheated state (b) the chart is for a given pressure (c) the chart is an approximation to true values (d) the mixtures can be treated as a perfect gas. |
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Answer» (b) the chart is for a given pressure |
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| 22. |
The sonic velocity in a fluid medium is directly proportional to (a) Mach number (b) pressure (c) square root of temperature (d) none of the above. |
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Answer» (c) square root of temperature |
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| 23. |
The region outside the Mach cone is called '(a) zone of action (b) zone of silence (c) control volume (d) none of the above. |
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Answer» (b) zone of silence |
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| 24. |
A convergent-divergent nozzle is used when the discharge pressure is (a) less than the critical pressure (b) equal to the critical pressure (c) more than the critical pressure (d) none of the above. |
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Answer» (a) less than the critical pressure |
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| 25. |
Calculate the ionization constant of 0.05M weak acid if it’s degree of dissociation is 0.018. |
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Answer» Ka = α2/C = (0.018)2/0.05 = 6.48 x 10-3 |
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| 26. |
Assertion :Phenol is weaker acid than ethanol. Reason:Ethanol is resonance stablised.A. If both Assertion `&` Reason are True `&` the Reason is a correct explanation of the Assertion.B. If both Assertion `&` Reason are True but Reason is not a correct explanation of the Assertion.C. If Assertion is True but the Reason is False.D. If both Assertion `&` Reason are False. |
| Answer» Correct Answer - D | |
| 27. |
`2xx10^(8)` atoms of carbon are arranged side by side. Calculate the radius of carbon atom if the length of this arrangement is `2.4 cm`. |
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Answer» Total length `=3.0 cm` Total number of atoms along the length `=2xx10^(8)` :. Diameter of each atom `=(3.0 cm)/(2xx10^(8))=1.5xx10^(-8) cm` :. Radius of the atom`=(1.5xx10^(-8)cm)/2=0.75xx10^(-8) cm` `=0.075xx10^(-7) cm` `0.075 10^(-9) m` `=0.075 nm` |
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| 28. |
The correct statement/statements is/are:A. The distance between two octahedral voids of a cubic close packing of atoms with radius `r` is `2r`B. The distance between two tetrahedral voids of a cubic close packing of atoms with radius `r` is `sqrt(6)xxr` at the body diagonal axesC. The distance between tetrahedral and octehedral void is `sqrt(3/2)xxr`, where is the radius of atom forming the close packingD. The distance between the surface of atoms `fcc` arrangement along an edge is `2(sqrt(2)-1)r` |
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Answer» Correct Answer - A::B::C::D abcd |
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| 29. |
Find out no of correct statements (A) `N_(2)gtN` (Ist ionization Energy) (B) `O_(2)gtO` (Ist Ionization Energy) (C) `H_(2)gtH` (Ist ionization Energy) (D) `N_(2)^(+)gtN_(2)^(-)` (Stability) (E) `O_(2)gtO` (Ist Electron affinity) (G) `Na_(2)CO_(3)gtLi_(2)CO_(3)` (Thermal stability) (H) NO of co-ordinate bond in `P_(4)O_(10)` is `4` (I) No of `pi` bond in `P_(4)O_(8)` is 2 |
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Answer» Correct Answer - 6 Correct statements `A,C,D,G,H,I` Incorrect statements `B,E,F` |
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| 30. |
Which of the following is/are can produce `H_(2)O_(2)` on hydrolysis?A. `BaO_(2)`B. `PbO_(2)`C. `MnO_(2)`D. `Na_(2)O_(2)` |
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Answer» Correct Answer - A::D ad `BaO_(2)` and `Na_(2)O_(2)` are peroxides |
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| 31. |
The correct order of hydration energy isA. `Li^(+) lt Na^(+) lt K^(+) lt Rb^(+)`B. `Li^(+) gt Na^(+) gt K^(+) gt Rb^(+)`C. `Li^(+) gt Rb^(+) gt K^(+) gt Na^(+)`D. `Li^(+) gt Rb^(+) gt Na^(+) gt K^(+)` |
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Answer» Correct Answer - B Hydraton energy `alpha1/("size of cation")` |
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| 32. |
A block of mass m is placed on a rough inclined plane. The corfficient of friction between the block and the plane is `mu` and the inclination of the plane is `theta`.Initially `theta=0` and the block will remain stationary on the plane. Now the inclination `theta` is gradually increased . The block presses theinclined plane with a force `mgcostheta`. So welding strength between the block and inclined is `mumgcostheta`, and the pulling forces is `mgsintheta`. As soon as the pulling force is greater than the welding strength, the welding breaks and the blocks starts sliding, the angle `theta` for which the block start sliding is called angle of repose `(lamda)`. During the contact, two contact forces are acting between the block and the inclined plane. The pressing reaction (Normal reaction) and the shear reaction (frictional force). The net contact force will be resultant of both. Answer the following questions based on above comprehension: Q. If `mu=(3)/(4)` then what will be frictional force (shear force) acting between the block and inclined plane when `theta=30^@`:A. `(3 sqrt(3))/(8)mg`B. `(mg)/(2)`C. `(sqrt(3))/(2)mg`D. zero |
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Answer» Correct Answer - B For `theta = 30^(@) ` and `mu=(3)/(4)` The pulling force downward (or down the incline) is `mg sin theta = mg sin(30^(@)) = (mg)/(2)` But the resisting force is friction Maximum friction force that can acts is `mu mg cos theta` `= (3)/(4)mg cos 30^(@) = (3 sqrt(3))/(8) mg` The frictional force is greater than the pulling force as `(3 sqrt(3))/(8) mg gt (mg)/(2)` `:.` block does not slide So the friction force acting on the block will be static friction and is equal to the pulling force `f = (mg)/(2)` |
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| 33. |
Number of atoms present in 224 `dm^(3)` of oxygen gas at STP is :-A. `6.0xx10^(23)`B. `1.2xx10^(23)`C. `6.0xx10^(24)`D. `1.2xx10^(25)` |
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Answer» Correct Answer - D Moles of `_(2)` at STP `=(224)/(22.4)=10` No on atoms `=10xx2xx6.02xx10^(23)` `=1.2xx10^(25)` atom |
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| 34. |
The ratio of de Broglie wavelength of a proton and a neutron moving with same velocity is nearlyA. `1`B. `sqrt(2)`C. `1// sqrt(2)`D. none of the above |
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Answer» Correct Answer - A `(lamda_(P))/(lamda_(N))=(((h)/(m_(P)V_(P))))/(((h)/(m_(N)V_(N))))=(m_(N))/(m_(P))` `(because V_(P)=V_(N))=1` |
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| 35. |
Identify the correct relationship:A. In `[Cu(NH_(3))_(4)]^(2+)` complex Hybrization of `Cu=dsp^(2)`B. `Fe(CO)_(x)` where `x` generally 5C. `Zn^(2+)` complexes with `sp^(3)d^(2)` hybridization are diamagnetic in natureD. `Cr^(3+)` complexes are paramagnetic in nature |
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Answer» Correct Answer - A::B::C::D abcd |
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| 36. |
The process of converting hydrated alumina into anhydrous alumina is called :A. RoastingB. CalcinationC. DressingD. Smelting |
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Answer» Correct Answer - B As a result of calcination, hydrated ore becomes anhydrous. |
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| 37. |
For the formation of atomic hydrogen from the molecular hydrogen, the favourable condition will be:-A. High temperature and high pressureB. Low temperature and low pressureC. High temperature and low pressureD. Low temperature and high pressure |
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Answer» Correct Answer - C `H_(2)(g)hArr2H(g) DeltaH=+ve` for forward reaction high temperature and law pressure. |
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| 38. |
The cost of electricity required to deposit `1g Mg` is Rs. 5.00. the cost of `30g` of `Al` to be deposited is Rs. `X`. Find the value of `x/40`? |
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Answer» Correct Answer - 5 `[5]` `Mg^(2+)+2e^(-)toMg(E_(Mg)=24/2=12g)` Charge required for the deposition of `12g Mg=1F` Charge required for the deposition of `1g Mg=1/12F` `:.` cost of `F/12` charge `= Rs. 5` `Al^(3+)+3e^(-)toAl(E_("Al")=27/3=9g)` Charge required for `9g=1F` Charge required for `30g=30/9F=(10F)/3` Cost for `(10F)/3` charge `=5xx12xx(10F)/3` `=Rs. 200` |
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| 39. |
In a crystal some iron are missing from normal sites. This is an example ofA. F-centresB. Interstitial defectC. Frenkel defectD. Schottky defect |
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Answer» Correct Answer - d Schottky defects are arised when one position ion and one negative ion are missing from their respectively position common in ionic compounds with high co-ordination number and havind almost similar size of cations and anions. |
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| 40. |
Nickel is purified by thermal decomposition of itsA. HydrideB. ChlorideC. AzideD. Carbonyl |
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Answer» Correct Answer - D Nickel is purified by thermal decomposition of nickel carbonyl `Ni(CO)_(4) overset("Heat") to Ni+4CO`. |
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| 41. |
Select the incorrect statement for a dry cell:A. ` Mn ` is reduced from ` +4 ` to ` +3` stateB. `NH_(3)` gas is liberated outC. Zn is used as anodeD. `A` pass of `NH_(4)Cl` and `ZnCl_(2)` |
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Answer» Correct Answer - B `NH_(3)` produced due of cathodic reaction. `MnO_(2) +NH_(4)^(+) +e rarr MnO(oM) +NH_(3) ` combines with `Zn^(2+)` to form `Zn(NH_(3))_(4)^(2+)`. |
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| 42. |
The rate constatnt of a second order reaction is ` 10^(-2) "mol"^(-1)` litre `sec^(-1)`. The rate constant when expressedd in ` cm^(3)" molecule"^(-1) "min"^(-1)` is :A. ` 9.96 xx 10-^(22)`B. ` 9. 96 xx 10^(23)`C. ` 9.96 xx 10^(21)`D. ` 1.004 xx 10^(-24)` |
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Answer» Correct Answer - A `K=10^(-2) "mol"^(-1)" litre "sec^(-1)` `=(10^(-2)xx1000xx60)/(6.02xx10^(22))c c "molecule"^(-1) "min"^(-1)`. `=9.9618xx10^(-22) cc "molecule"^(-1) "minm"^(-1)` |
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| 43. |
Which statement about enzymes is not corect ?A. Enzymes are in colloidal stateB. Enxymes can acts as catalystC. Enzymes cab catalyse any reactionD. Urease is an ezzyme |
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Answer» Correct Answer - C Enzyme catalysed reactions are highly specific , i.e., one enzyme catalyses only one reaction. |
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| 44. |
Proof spirit contains.A. 50% alcohol by volumeB. 40% alcohol by volumeC. 57.1% alcohol by volumeD. 49.3% alcohol by volume |
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Answer» Correct Answer - C `57.1%` alcohol by volume and `48%` by mass. |
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| 45. |
Which of the following compounds is not a Lewis base ?A. Diethyl ether +`CI_(2)`B. t-butyl alcoholC. propaoneD. `:C CI_(2)` |
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Answer» Correct Answer - D Dichloro methylene (carbene or `:CCI_2`) is an electron dificient species and hence a Lewis acid. |
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| 46. |
Which of the following reagents can be used for separating a mixture of ehter and alkyl halide ?A. Dil. `H_2SO_4`B. Conc.`H_2SO_4`C. Alk. `KMnO_4`D. Acidic `K_2Cr_2O_7` |
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Answer» Correct Answer - B Ethers form soluble dialkyl oxonium hydrogen sulphate with conc. `H_2SO_4` while alkyl halides are not soluble in conc. `H_2SO_4` |
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| 47. |
Which of the following alkyl halides is most reactive in the Williamson reaction ?A. B. C. D. |
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Answer» Correct Answer - B Allyl bromide `(CH_2=CH-CH_2-Br)` Which is `1^(@)` alkyl halide and allylic carbocation is resonance stablised also. |
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| 48. |
What happens when ionic hydrides of s-block elements in molten state are electrolysed?A. Hydride ion migrates at cathodeB. Dihydrogen is liberated at cathodeC. Hydride ion reforms metal hydrideD. Dihydrogen is liberated at anode |
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Answer» Correct Answer - D When ionic hydrides of s-block elements are subjected to electrolysis, dihydrogen gas is liberated at anode which confirms the existence of hydrogen in the form of hydride ion `(H^(-))`. Following reactions takes place: `MH(l)hArrM^(+)(aq)+H^(-)(aq)` At cathode `M^(+)(aq)+e^(-)toM(s)` At anode `2H^(-)(aq)-2e^(-)to2H(g)` `H+HtoH_(2)(g)` |
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| 49. |
The ore that is concentrated by froth floatation process isA. cinnabarB. bauxiteC. malachiteD. zincite |
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Answer» Correct Answer - A Froth floatation process is used for concentration of sulphide ores only. Thus , cinnabar, i.e., HgS is concentrated by this method . |
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| 50. |
Which of following is not a property of red phosphorus?A. Insoluble in carbon disulphideB. It does not show chemiluminescence by action of airC. It forms phosphine when treated with hot sodium hydroxide solutionD. It is non-poisonous |
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Answer» Correct Answer - C Red phosphorus possess iron grey lustre. It is odourless, non-poisonous and insoluble in water as in carbon disulphide. It does not show chemalumiscence by action ot air. Thus, the option (c) is correct. |
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