Recent questions tagged 29

The correct structure of tribromooctaoxide is :-

asked Jul 10, 2019 by pady_1

2 answers

An object is placed 40 cm in front of a convex mirror of radius of curvature 20 cm. The image :

asked Dec 19, 2018 by pady_1

0 answers

In a medium, in which a transverse progressive wave is travelling to the phase difference between two points with a distance of separation is $1.25\;cm$ is $\frac{\pi}{4}$. If the frequency of wave is $1000\;Hz$, its velocity will be :

asked Dec 19, 2018 by pady_1

0 answers

A ball is projected vertically down with an initial velocity from a height of 20 m on to a horizontal floor. During the impact it losses 50% of the energy and rebounds to the same height, the initial velocity of its projection is :

asked Dec 19, 2018 by pady_1

0 answers

A heavy nucleus at rest breaks into two fragments which fly off with velocities in the ratio $3:1$. The ratio of radii of the fragments is :

asked Dec 11, 2018 by pady_1

0 answers

Identify the pair whose dimension are equal :

asked Dec 11, 2018 by pady_1

1 answer

Consider the following two statements : A. Linear momentum of a system of particles is zero. B. Kinetic energy of a system of particle is zero. Then :

asked Dec 11, 2018 by pady_1

0 answers

Two moles of an ideal monoatomic gas occupies a volume $V$ at $27^{\circ}C$. The gas expands adiabatically to a volume $2V$. Calculate (a) the final temperature of the gas and (b) change in its internal energy.

asked Dec 11, 2018 by pady_1

0 answers

If, for a positive integer n, the quadratic equation, $x(x + 1) + (x + 1)(x + 2) +.....+ (x + \overline{n – 1})(x + n) = 10n$ has two consecutive integral solutions, then n is equal to

asked Dec 11, 2018 by pady_1

1 answer

Identify the semiconductor devices whose characteristics are given below, in the order (a), (b), (c), (d) :

asked Dec 11, 2018 by pady_1

0 answers

In an unbiased n-p junction electrons diffuse from n - region to p - region because :

asked Dec 11, 2018 by pady_1

0 answers

Two beams, A and B, of plane polarized light with mutually perpendicular planes of polarization are seen through a polaroid. From the position when the beam A has maximum intensity (and beam B has zero intensity), a rotation of Polaroid through $30^{\circ}$ makes the two beams appear equally bright. If the initial intensities of the two beams are $I_A$ and $I_B$ respectively, then $I_A/I_B$ equals :

asked Dec 11, 2018 by pady_1

0 answers

An organic compound A upon reacting with $NH_3$ gives B. On heating B gives C. C in presence of KOH reacts with $Br_2$ to give $CH_3CH_2NH_2$. A is

asked Dec 11, 2018 by pady_1

0 answers

A line is drawn through the point (1, 2) to meet the coordinate axes at P and Q such that it forms a triangle OPQ, where O is the origin. If the area of the triangle OPQ is least, then the slope of the line PQ is

asked Dec 11, 2018 by pady_1

0 answers

The half life of a radioactive substance is 20 minutes. The aproximate time interval $(t_2 - t_1)$ between the time $t_2$ when $\frac{2}{3}$ of it has decayed and time $t_1$ and $\frac{1}{3}$ of it had decayed is :

asked Dec 11, 2018 by pady_1

0 answers

The polymer containing strong intermolecular forces e.g. hydrogen bonding,

asked Dec 11, 2018 by pady_1

0 answers

The work done on the gas in taking it from D to A is

asked Nov 29, 2018 by pady_1

0 answers

$Let I ={\displaystyle\int^1_0\frac{sin{x}}{\sqrt{x}}dx}$ and $ J={\displaystyle\int^1_0\frac{cos{x}}{\sqrt{x}}dx}$. Then which one of the following is true?

asked Nov 29, 2018 by pady_1

0 answers

If (2, 3, 5) is one end of a diameter of the sphere $x^2 + y^2 + z^2 - 6x - 12 y - 2 z + 20 = 0 $, then the coordinates of the other end of the diameter are :

asked Nov 29, 2018 by pady_1

0 answers

Two insulating plates are both uniformly charged in such a way that the potential difference between them is $V_2 -V_1 = 20 V$.(i.e, plate 2 is at a higher potential). The plates are separated by $d=0.1 \;m$ and can be treated as infinitely large. An electron is released from rest on the inner surface of plate 1. What is its speed when it hits plate 2 ? ($e = 1.6 \times 10^{-19} C, m_0 = 9.11 \times 10^{-31} kg$)

asked Nov 13, 2018 by pady_1

0 answers

In a triangle ABC, let $\angle{C} = \pi / 2$, if $r$ is the inradius and $R$ is the circumradius of the triangle ABC, then $2(r+R)$ equals :

asked Nov 5, 2018 by pady_1

0 answers

The electrical conductivity of a semiconductor increases when electromagnetic radiation of wavelength shorter than 2480 nm, is incident on it. The band gap in (eV) for the semiconductor is :

asked Nov 5, 2018 by pady_1

0 answers

Let $f(x) = \frac{1- \tan x}{4x - \pi}, \; x \neq \frac{\pi}{4} , \; x \in [0, \frac{\pi}{2}]$. If $f(x)$ is continuous in $[0, \frac{\pi}{2}]$, then $f(\frac{\pi}{4})$ is

asked Nov 5, 2018 by pady_1

0 answers

If the mass of the Sun were ten times smaller and the universal gravitational constant were ten times larger in magnitude, which of the following is not correct ?

asked Aug 21, 2018 by pady_1

1 answer

Machanism of a hypothetical reaction $X_2 + Y_2 \to 2XY$ is given below. (i) $X_2 \to X + X (fast)$ (ii) $X + Y_2 \rightleftharpoons XY + Y (slow)$ (iii) $X + Y \to XY (fast) $ The overall order of the reaction will be -

asked Aug 21, 2018 by pady_1

1 answer

Lithium has a bcc structure. Its density is $530\; kg\; m^{–3}$ and its atomic mass is $6.94\; g \;mol^{–1}$. Calculate the edge length of a unit cell of Lithium metal. (NA = $6.02 \times 10^{23} mol^{–1}$)

asked Aug 21, 2018 by pady_1

1 answer

Two possible stero-structuers of $CH_3CHOH.COOH$, which are optically active, are called :

asked Aug 21, 2018 by pady_1

1 answer

Following figures show the arrangement of bar magnets in different configurations. Each magnet has magnetic dipole $\overrightarrow{m}$ . Which configuration has highest net magnetic dipole moment?

asked Aug 20, 2018 by pady_1

1 answer

A current loop in a magnetic field -

asked Aug 20, 2018 by pady_1

1 answer

An electric dipole of moment 'p' is placed in an electric field of intensity 'E'. The dipole acquires a position such that the axis of the dipole makes an angle $\theta$ with the direction of the field.Assuming that the potential energy of the dipole to be zero when $\theta = 90º$, the torque and the potential energy of thedipole will respectively be

asked Aug 20, 2018 by pady_1

1 answer

When 1 kg of ice at $0^oC$ melts to water at $0^oC$, the resulting change in its entropy, taking latent heat of ice to be $80 \; Cal/gm$ is :

asked Aug 16, 2018 by pady_1

1 answer

Which of the following statement is false for the properties of electromagnetic 2 waves ?

asked Jul 26, 2018 by pady_1

1 answer

A conducting circular loop is placed in a uniform magnetic field 0.04T with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at 2 mm/s. The induced emf in the loop when the redius is 2 cm is :

asked Jul 26, 2018 by pady_1

1 answer

The energy required to charge a parallel plate condenser of plate separation d and plate area of cross-section A such that the uniform electric field between the plates is E, is :

asked Jul 26, 2018 by pady_1

1 answer

If the cold junction of a thermo-couple is kept at $0^{\circ}C$ and the hot junction is kept at $T^{\circ}C$, then the relation between neutral temperature $(T_n)$ and temperature of inversion $(T_i)$ is:

asked Jul 26, 2018 by pady_1

1 answer

A 0.5 kg ball moving with a speed of 12 m/s strikes a hard wall at an angle of 30Âº with the wall. It is reflected with the same speed and at the same angle. If the ball is in contact with the wall for 0.25 seconds, the average force acting on the wall is:-

asked Jul 25, 2018 by pady_1

1 answer

Copper has face centered cubic (fcc) lattice with interatomic spacing equal to 2.54Å. The value of lattice constant for this lattice is-

asked Jul 24, 2018 by pady_1

1 answer

A ball of mass 2 kg and another of mass 4 kg are dropped together from a 60 feet tall building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in t the ratio of-

asked Jul 24, 2018 by pady_1

1 answer

Two 220 volt, 100 watt bulbs are connected first in series and then in parallel. Each time the combination is connected to a 220 volt a.c. supply line. The power drawn by the combination in each case respectively will be :

asked Jul 24, 2018 by pady_1

1 answer

A rod of length is 3m and its mass acting per unit length is driectly proportional to distance x from one of its end then its centre of gravity from th end will be at : -

asked Jul 23, 2018 by pady_1

1 answer

Energy per unit volume for a capacitor having area A and separation d kept at potential difference V is given by :-

asked Jul 20, 2018 by pady_1

1 answer

The relation between $\lambda$ and $T_\frac{1}{2}$ is : ( $T_\frac{1}{2}$= half life , $\lambda\rightarrow decay constant$ )

asked Jul 20, 2018 by pady_1

1 answer

A gas of volume changes 2 litre to 10 litre at constant temperature 300K, then the change in internal energy will be :

asked Jun 15, 2018 by pady_1

1 answer

Brooke bought 5 packs of white T-shirts and 2 packs of blue T-shirts for her basketball team. The white T-shirts come in packs of 9, and the blue T-shirts come in packs of 6. How many T-shirts did Brooke buy in all?

asked Dec 31, 2015 by pady_1

1 answer

Brenna is planting flowers in her garden. She plants 2 flowers in the first row, 6 flowers in the second row, 18 flowers in the third row, and 54 flowers in the fourth row. If this pattern continues, how many flowers will Brenna plant in the fifth row?

asked Dec 31, 2015 by pady_1

0 answers

John bought 27.5 m of cloth. How many cm of cloth did he buy?

asked Dec 31, 2015 by pady_1

1 answer

$6 \large\frac{2}{3} \div 4\large\frac{1}{5}$

asked Dec 31, 2015 by pady_1

0 answers

If 95 \% of the students are present in a school and the number of absent students is 25, find the total number of students in the school?

asked Dec 31, 2015 by pady_1

0 answers

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