Email
Chat with tutors
Login
Ask Questions, Get Answers
Menu
X
home
ask
tuition
questions
practice
papers
mobile
tutors
pricing
X
Answers posted by pady_1
Questions
4370
answers
1
best answer
0
votes
If $ y =\large\frac{\log_{\Large e}x}{x}$ and $z= \log_ ex,$ then $\large\frac{d^2y}{dz^2}+\frac{dy}{dx}=$
answered
Nov 7, 2013
$ (d)\;-e^{-z}$
0
votes
If $f(x) =|x|+ | \sin x|$ for $x \in \bigg(-\large\frac{\pi}{2},\frac{\pi}{2}\bigg),$ then its left hand derivative at $x=0$ is
answered
Nov 7, 2013
(c) -2
0
votes
If $\cos^{-1}\bigg(\large\frac{x^2-y^2}{x^2+y^2}\bigg)=k$ (a constant ), then $\large\frac{dy}{dx}=$
answered
Nov 7, 2013
$(a)\;\frac{y}{x}$
0
votes
If [x] denotes the greatest integer not exceeding x and if the function f defined by \[f(x) = \left\{ \begin{array}{l l} \frac{a+2 \cos x}{x^2} & \quad ( x < 0) \\ b\;\tan \frac{\pi}{[x+4]} & \quad (x \geq 0) \end{array} \right. \] is continuous at $x=0,$ then the ordered pair $(a,b)=$
answered
Nov 7, 2013
(b) (-2,-1)
0
votes
$\lim\limits_{x \to 8} \large\frac{\sqrt {1+\sqrt {1+x}}-2}{x-8}=$
answered
Nov 7, 2013
$(c) \frac{1}{24}$
0
votes
Identify Phenacetin from the following :
answered
Nov 7, 2013
(d)
0
votes
The number of hydrogen bonds between Guanine & Cytosine; and between Adenine & Thymine in DNA is :
answered
Nov 7, 2013
(b) 3,2
0
votes
Example of a biodegradable polymer pair is :
answered
Nov 7, 2013
(b) PHBV and Dextron
0
votes
Identify $X$and $Y$ in the following reactions:
answered
Nov 7, 2013
(c)
0
votes
The $pK_a$ values of four carboxylic acids are given below. Identify the weakest carboxylic acid.
answered
Nov 7, 2013
(a) 4.89
0
votes
The structure of PCC is :
answered
Nov 7, 2013
(d) $C_5H_5 NHC_r O_3 Cl^{-}$
0
votes
The product formed in the reaction of phenol with $Br_2$ dissolved in $CS_2$ at $0^{\circ}$ are :
answered
Nov 7, 2013
(b) o-bromo and p-bromophenols
1
vote
Heating chloroform with aqueous sodium hydroxide solution forms:
answered
Nov 7, 2013
(c) Sodium formate
0
votes
In which of the following properties, the two enantiomers of lactic acid differ from each other?
answered
Nov 7, 2013
(a) Sign of specific rotation
0
votes
Assertion (A): $-NH_2$ group of aniline is ortho, para directing in electrophilic substitutions. Reason (R) : $-NH_2$ group stabilizes the arenium ion formed by the ortho, para attack of the electrophile.
answered
Nov 7, 2013
(a) Both (A) and (R) are correct, (R) is the correct explanation of (A)
0
votes
$C_2H_6 \to C_2H_4+H_2$ above reaction is called as ___________ .
answered
Nov 7, 2013
(c) Pyrolysis
0
votes
Which one of the following gives Prussion blue colour?
answered
Nov 7, 2013
$(d)\;Fe_4[Fe(CN)_6]_3$
0
votes
Which of the following is not added during the extraction of silver by cyanide process?
answered
Nov 7, 2013
(d) Na_2S_2O_3
0
votes
Cataract and skin cancer are caused by _________ .
answered
Nov 7, 2013
(b) Depletion of Ozone layer
0
votes
A compound absorbs light in the wavelength region 490-500 nm. Its complementary colour is:
answered
Nov 7, 2013
(a) Red
0
votes
Liquid $\underline{X}$ is used in Bubble chamber to detect neutral mesons and gamma photons. Then ,$\underline{X}= \underline{X}$
answered
Nov 7, 2013
(d) Xe
0
votes
Which one of the following is not correct?
answered
Nov 7, 2013
(c) Pyrophosphoric acid contains two $P-H$ bonds
0
votes
$Na_2S_2O_3$ reacts with moist $Cl_2$ to from $Na_2SO_4,HCl$ and $\underline{X}.$ Which one of the following is $\underline{X}$?
answered
Nov 7, 2013
$(d) S$
0
votes
The role of copper diaphragm in Whytlaw-Gray's method is :
answered
Nov 7, 2013
(b) preventing the mixing of $H_2$ and $F_2$
0
votes
How many corner's of $SiO_4$ unit are shared in the formation of three dimensional silicates?
answered
Nov 7, 2013
(c) 4
0
votes
Diborane reacts with HCl in the presence of $AlCl_3$ and liberates:
answered
Nov 7, 2013
$(a)\;H_2$
0
votes
Solution "X" contains $Na_2 CO_3$ and $NaHCO_3.\;20 \;ml$ of $X$ when titrated using methyl orange indicator consumed $60\; ml $ of $0.1\;M\;HCl$ solution. In another experiment, $20 \;ml$ of X solution when titrated using phenolphthalein consumed $20\;ml$ of $0.1\;M\;HCl$ solution. The concentration (in mol $lit^{-1}$) of $Na_2CO_3$ and $NaHCO_3$ in X are respectively.
answered
Nov 7, 2013
(b) 0.1,0.1
0
votes
Observe the following statements:
answered
Nov 7, 2013
(a) 1& 3
0
votes
For which one of the following reactions,the entropy change is positive?
answered
Nov 7, 2013
(d) $H_2O \to H_2O$
0
votes
Match the following
answered
Nov 7, 2013
(a)
0
votes
The degree of ionization of $\;0.10\;M$ lactic acid is $4.0 \%$
answered
Nov 7, 2013
(b) $1.66 \times 10^{-4}$
0
votes
The $pH$ of a buffer solution made by mixing $25\;ml$ of $\;0.02\;M\;NH_4OH$ and $25\;ml$ of $\;0.2\;M\;NH_4Cl$ at $25^{\circ}C$ is : $(pK_b\;of\;NH_4OH=4.8)$
answered
Nov 7, 2013
(b) 8.2
0
votes
Which one of the following plots is correct for a first reaction?
answered
Nov 7, 2013
(c)
0
votes
The number of octahedral and tetrahedral holes respectively present in a hexagonal close packed (hcp) crystal of 'X' atoms are :
answered
Nov 7, 2013
(b) X,X
0
votes
The vapour pressure in mm of $Hg,$ of an aqueous solution obtained by adding 18 g of glucose $(C_6H_{12}O_6)$ to $180\;g$ of water at $100^{\circ}$ is :
answered
Nov 7, 2013
(d) 752.4
0
votes
Which one of the following is an isotonic pair of solutions?
answered
Nov 7, 2013
$(a)\;0.15\;M\;NaCl\;and\;0.1\;M\;Na_2SO_4$
0
votes
At $T(k),$ the ratio of kinetic energies of $4\;g$ of $H_{2_{(g)}}$ and $8\;g$ of $O_{2_{g}}$ is :
answered
Nov 7, 2013
(d) 8.1
0
votes
Which one of the following statement is correct?
answered
Nov 7, 2013
(b) Laternal overlap of p-orbitals or p- and d-orbitals produces $\pi$ bonds
0
votes
Identify the correct set:
answered
Nov 7, 2013
(c)
0
votes
The number of elements present in fourth period is :
answered
Nov 7, 2013
(c) 18
0
votes
The basic of quantum mechanical model of an atom is :
answered
Nov 7, 2013
(c) dual nature of electron
0
votes
The number of radial nodes of $3s$ and $2p$ orbitals respectively are :
answered
Nov 7, 2013
(b) 2,0
0
votes
Of the following, $NAND$ gate is
answered
Nov 7, 2013
(d)
0
votes
The base current in a transistor circuit changes from $45\;\mu A$ to $140\;mu A$. Accordingly, the collector current changes from $0.2\;mA$ to $4.00\;mA$. The gain in current is
answered
Nov 7, 2013
(c) 40
0
votes
A $U^{235}$ nuclear reactor generates energy at a rate of $3.70 \times 10^7\; J/s$ Each fission liberates $185\;MeV$ useful energy. If the reactor has to operate for $144 \times 10^4$ seconds, then the mass of the fuel needed is (Assume Avogadro's number $=6 \times 10^{23} \;mol^{-1},1 eV=1.6 \times 10^{-19}\;J)$
answered
Nov 7, 2013
$(b)\;0.705\;kg$
0
votes
The radius of $_{72}Te^{125}$ nucleus is $6$ fermi . The radius of $_{13}AI^{27}$ nucleus in meters is
answered
Nov 7, 2013
$(b)\;3.6 \times 10^{-15}\;m$
0
votes
The work function of a metal is $2$ eV. If a radiation of wavelength 3000 A is incident on it, the maximum kinetic energy of the emitted photo electrons is
answered
Nov 7, 2013
$(c)\;3.4 \times 10^{-9}\;J$
0
votes
Initially a photon of wavelength $\lambda _1$ falls on photocathode and emits an electron of maximum energy $E_1$. If the wave length of the incident photon i changed to $\lambda _2$, the maximum energy of the electron emitted becomes $E_2$. Then value of hc (h= Planck's constant , c= velocity of light) is
answered
Nov 7, 2013
$(b)\;hc= \frac{(E_1-E_2)}{\lambda _2 - \lambda_1}.(\lambda _1. \lambda _2)$
0
votes
The sensitivity of a galvanometer that measures current is decreased by $\large\frac{1}{40}$ times by using shunt resistance of $10 \;\Omega$. Then, the value of the resistance of the galvanometer is
answered
Nov 7, 2013
(a) $390\; \Omega$
0
votes
A series $LCR$ circuit is connected across a source of alternating emf of changing frequency and resonates at frequency $f_0$. Keeping capacitance constant, if the inductance (L) is increased by $\sqrt 3$ times and resistance is increased (R) by 1.4 times, the resonant frequency now is
answered
Nov 7, 2013
$(d)\;\bigg(\frac{1}{3}\bigg)^{1/4}f_0$
Page:
« prev
1
...
81
82
83
84
85
86
87
88
next »
Home
Ask
Tuition
Questions
Practice
Your payment for
is successful.
Continue
...