Recent questions tagged 69

Six similar bulbs are connected as shown in the figure with a DC source of emf E, and zero internal resistance. The ratio of power consumption by the bulbs when (i) all are glowing and (ii) in the situation when two from section A and one from section B are glowing, will be :

asked Jul 8, 2019 by pady_1

1 answer

The cell reaction of a cell is $Mg_{(s)} + Cu^{2+}_{(aq)} \to Cu_{(s)} + Mg^{2+}_{(aq)}$ If the standard reduction potentials of magnesium and copper are $-0.33$ and $+2.38\; V$ respectively, the e.m.f of the cell is:

asked Dec 19, 2018 by pady_1

0 answers

The half-life of a first order reaction is 10 sec. What is its rate constant (in $sec^{-1}$) ?

asked Dec 19, 2018 by pady_1

0 answers

Which of the following reacts with ammonical cuprous chloride ?

asked Dec 19, 2018 by pady_1

1 answer

Consider the following reactions $C_2H_2 \xrightarrow[\text{500$^{\circ}$C}]{\text{red hot iron tube}} A$ $A \xrightarrow[\text{70$^{\circ}$C}]{\text{conc. $HNO_3$, conc. $H_2SO_4$}} B$ $B \xrightarrow{LiAlH_4} C_6H_5 - N = N - C_6H_5$ A and B are :

asked Dec 11, 2018 by pady_1

0 answers

One end of massless rope, which passes over a massless and frictionless pulley $P$ is tied to a hook $C$ while the other end is free. Maximum tension that the rope can bear is 360 N. With what value of maximum safe acceleration (in $ms^{-2}$) can a man of 60 kg climb on the rope ?

asked Dec 11, 2018 by pady_1

1 answer

Three charges $-q_1,\;+q_2$ and $-q_3$ are placed as shown in the figure. The x-component of the force on $-q_1$ is proportional to :

asked Dec 11, 2018 by pady_1

1 answer

The major product formed in the following reaction is :

asked Dec 11, 2018 by pady_1

0 answers

In the following reactions, $ZnO$ is respectively acting as a/an : (a) $ZnO + Na_2O \to Na_2ZnO_2$ (b) $ZnO + CO_2 \to ZnCO_3$

asked Dec 11, 2018 by pady_1

0 answers

If the sum of the first ten terms of the series $(1 + \frac{3}{5})^2 + ( 2 + \frac{2}{5})^2 + (3 + \frac{1}{5})^2 + 4^2 + (4 + \frac{4}{5})^2......,$ is $\frac{16}{5} m$, then $m$ is equal to :

asked Dec 11, 2018 by pady_1

1 answer

The value of $\displaystyle\sum_{r=16}^{30} (r+2)(r-3)$ is equal to :

asked Dec 11, 2018 by pady_1

1 answer

The octahedral complex of a metal ion $M^{3+}$ with four monodentate ligands $L_1, L_2, L_3$ and $L_4$ absorb wavelengths in the region of red, green, yellow and blue, respectively. The increasing order of ligand strength of the four ligands is:

asked Dec 11, 2018 by pady_1

0 answers

A metallic rod of length $â€˜lâ€™$ is tied to a string of length $2l$ and made to rotate with angular speed $\omega$ on a horizontal table with one end of the string fixed. If there is a vertical magnetic field â€˜Bâ€™ in the region, the e.m.f. induced across the ends of the rod is:

asked Dec 11, 2018 by pady_1

0 answers

Which of the following on thermal decomposition yields a basic as well as an acidic oxide ?

asked Dec 11, 2018 by pady_1

0 answers

A vessel at 1000 K contains $CO_2$ with a pressure of 0.5 atm. Some of the $CO_2$ is converted into $CO$ on the addition of graphite. If the total pressure at equilibrium is 0.8 atm, the value of $K$ is

asked Dec 11, 2018 by pady_1

0 answers

Consider the following relations : $R = \{ (x, y) | x, \; y$ are real number and $x = wy$ for some rational number $w \}$; $S = \{ (\frac{m}{n}, \frac{p}{q} ) | m, \; n, \; p $ and $q$ are integers such that $n, \;q \neq 0$ and $qm = pn \}$. Then

asked Dec 11, 2018 by pady_1

0 answers

From 6 different novels and 3 different dictionaries, 4 novels and 1 dictionary are to be selected and arranged in a row on the shelf so that the dictionary is always in the middle. Then the number of such arrangements is

asked Nov 29, 2018 by pady_1

0 answers

The correct decreasing order of priority for the functional groups of organic compounds in the IUPAC system of nomenclature is

asked Nov 29, 2018 by pady_1

0 answers

The resistance of a wire is $5 \Omega$ at $50^{\circ}C$ and $6 \Omega$ at $100^{\circ} C$. The resistance of the wire at $0^{\circ} C$ will be :

asked Nov 29, 2018 by pady_1

0 answers

$CH_3Br + Nu^- \to CH_3 - Nu + Br^-$ The decreasing order of the rate of the above reaction with nucleophiles $(Nu^-)$ A to D is : [$Nu^- = (A)\; PhO,\; (B)\; AcO^-,\; (C)\; HO^-\; (D)\; CH_3O$]

asked Nov 13, 2018 by pady_1

0 answers

If both the roots of the quadratic equation $x^2-2kx + k^2+k - 5 = 0$ are less than 5, then $k$ lies in the interval :

asked Nov 5, 2018 by pady_1

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A circuit has a resistance of $12 \Omega$ and an impedance of $15 \Omega$. The power factor of the circuit will be :

asked Nov 5, 2018 by pady_1

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The mean and the variance of a binomial distribution are 4 and 2 respectively. Then the probability of 2 successes is

asked Nov 5, 2018 by pady_1

0 answers

Which one is a wrong statement ?

asked Aug 21, 2018 by pady_1

1 answer

Which of the following are found is extreme saline conditions ?

asked Aug 21, 2018 by pady_1

1 answer

Spindle fibres attach on to

asked Aug 21, 2018 by pady_1

1 answer

Male gametophyte in angiosperms produces

asked Aug 21, 2018 by pady_1

2 answers

Artificial sweetner which is stable under cold conditions only is :

asked Aug 20, 2018 by pady_1

1 answer

$XeF_2$ is isostructural with-

asked Aug 20, 2018 by pady_1

1 answer

A metal crystallizes with a face-centered cubic lattice. The edge of the unit cell is 408 pm. The diameter of the metal atom is

asked Aug 20, 2018 by pady_1

1 answer

Enthalpy change for the reaction, $4H_{(g)} \to 2H_{2(g)}$ is $–869.6\;kJ$ The dissociation energy of H – H bond is

asked Aug 16, 2018 by pady_1

2 answers

Acetamide is treated with the following reagents separately. Which one of these would yield methyl amine?

asked Jul 26, 2018 by pady_1

1 answer

In which of the following molecules / ions $BF_3,NO{_2}{^-},NH{_2}{^-},H{_2}$ and the central atom is $sp^2$ hybridized ?

asked Jul 26, 2018 by pady_1

1 answer

How many moles of lead (II) chloride will be formed from a reaction between 6.5 g of PbO and 3.2 g of HCl ?

asked Jul 26, 2018 by pady_1

0 answers

Identify the correct order of the size of the following :

asked Jul 26, 2018 by pady_1

1 answer

For the reaction : $CH_4(g)+2O_2(g)\rightleftharpoons CO_2(g)+2H_2O(l)$ $\Delta H_{r}=-170.8KJ mol^{-1}$ Which of the following statements is not true:-

asked Jul 25, 2018 by pady_1

0 answers

The surface tension of which of the following liquid is maximum :-

asked Jul 24, 2018 by pady_1

1 answer

The helical structure of protein is stabilized by:-

asked Jul 24, 2018 by pady_1

1 answer

For which one of the following equations is $\Delta H^{\circ}_{react}$ equal to $\Delta H^o_f$ for the product :

asked Jul 24, 2018 by pady_1

1 answer

In electrolysis of NaCl when Pt electrode is taken then $H_2$ is liberated at cathode while with Hg cathode it forms sodium amalgam : -

asked Jul 23, 2018 by pady_1

1 answer

When 1 mol gas is heated at constant volume temperature is raised from 298 to 308 K. Heat supplied to the gas is 500 J. Then which statement is correct : -

asked Jul 20, 2018 by pady_1

1 answer

For a any reversible reaction. If increases concentration of reactants. Then effect on equilibrium constant :

asked Jul 20, 2018 by pady_1

1 answer

The concentration of $ZnCl_{2}$ solution will change when it is placed in a container which is made of :

asked Jun 15, 2018 by pady_1

1 answer

Six friends P, Q, R, S, T and U are sitting around a circular table. U is sitting between P and R, Q is sitting between T and S. If P is sitting on right of S, who is sitting between U and S ?

asked Dec 31, 2015 by pady_1

1 answer

Type the missing number in this sequence: 38, 47, 56, 65, 74, ------

asked Dec 31, 2015 by pady_1

0 answers

Convert: 46 mm = ...... cm ...... mm

asked Dec 31, 2015 by pady_1

0 answers

Out of a class of 150, one-third opted for German, two-fifth for Italian and rest for French. Find how many opted for French?

asked Dec 31, 2015 by pady_1

1 answer

A man bought 360 eggs at \$ 18 per dozen. 40 egg where broken and 20 egg were rotten. What would be his profit or loss if he sells the rest at \$ 20 per dozen?

asked Dec 31, 2015 by pady_1

1 answer

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