Recent questions tagged 9

Which of the following diatomic molecular species has only $\pi$ bonds according to Molecular Orbital theory?

asked Jul 8, 2019 by pady_1

1 answer

The position of a particle is given by $\overrightarrow{r} = (\hat{i} + 2 \hat{j} - \hat{k} )$ momentum $\overrightarrow{p} = ( 3 \hat{i} + 4 \hat{j} - 2 \hat{k})$. The angular momentum is perpendicular to :

asked Dec 19, 2018 by pady_1

0 answers

The dimensional formula for latent heat is :

asked Dec 19, 2018 by pady_1

0 answers

Consider the following statements A and B and identify the correct choice in the given answers : (A) Line spectra is due to atoms in gaseous state. (B) Band spectra is due to molecules

asked Dec 19, 2018 by pady_1

0 answers

The difference in the number of wavelengths, when yellow light propagates through air and vacuum columns of the same thickness, is one. The thickness of the air column is : Refractive index of air $\mu_c = 1.0003$ Wavelength of yellow light in vacuum = $6000 \; \mathring{A}$

asked Dec 11, 2018 by pady_1

0 answers

A wire when connected to 220 V mains supply has power dissipation $P_1$. Now the wire is cut into two equal piece which are connected in parallel to the same supply. Power dissipation in this case is $P_2$. Then $P_2 : P_1$ is :

asked Dec 11, 2018 by pady_1

0 answers

A strip of copper and another of germanium are cooled from room temperature to 80 K. The resistance of :

asked Dec 11, 2018 by pady_1

0 answers

An electron from various excited states of hydrogen atom emit radiation of come to the ground state. Let $\lambda_n\; \lambda_g$ be the de Broglie wavelength of the electron in the $n^{th}$ state and the ground state respectively. Let $ \bigwedge_{n}$ be the wavelength of the emitted photon in transition from the $n^{th}$ state to the ground state. For large $n$ (A, B are constants)

asked Dec 11, 2018 by pady_1

0 answers

If the image of the point P(1, -2, 3) in the plane $2x + 3y - 4z + 22 =0$ measured parallel to the line, $\frac{x}{1} = \frac{y}{4} = \frac{z}{5}$ is $Q$, then $PQ$ is equal to :

asked Dec 11, 2018 by pady_1

1 answer

$'nâ€™$ moles of an ideal gas undergoes a process $A \to B$ as shown in the figure. The maximum temperature of the gas during the process will be :

asked Dec 11, 2018 by pady_1

0 answers

If two glass plates have water between them and are separated by very small distance (see figure), it is very difficult to pull them apart. It is because the water in between forms cylindrical surface on the side that gives rise to lower pressure in the water in comparison to atmosphere. If the radius of the cylindrical surface is R and surface tension of water is T then the pressure in water between the plates is lower by :

asked Dec 11, 2018 by pady_1

0 answers

Four particles, each of mass M and equidistant from each other, move along a circle of radius R under the action of their mutual gravitational attraction. The speed of each particle is :

asked Dec 11, 2018 by pady_1

0 answers

How many litres of water must be added to 1 litre of an awueous solution of HCl with a pH of 1 to create an aqueous solution with pH of 2 ?

asked Dec 11, 2018 by pady_1

0 answers

If $n$ is a positive integer, then $(\sqrt{3} + 1)^{2n} - (\sqrt{3} - 1)^{2n}$ is

asked Dec 11, 2018 by pady_1

1 answer

A boat is moving due east in a region where the earth's magnetic field is $5.0 \times 10^{-5} NA^{-1}m^{-1}$ due north and horiontal. The boat carries a vertical aerial 2m long. If the speed of the boat is $1.50 \;ms^{-1}$, the magnitude of the induced emf in the wire of aerial is :

asked Dec 11, 2018 by pady_1

0 answers

In the chemical reactions, the compounds ‘A’ and ‘B’ respectively are

asked Dec 11, 2018 by pady_1

0 answers

The transition from the state $n=4$ to $n=3$ in a hydrogen like atom results in ultraviolet radiation. Infrared radiation will be obtained in the transition from

asked Nov 29, 2018 by pady_1

0 answers

1. Let R be the real line. Consider the following subsets of the plane $R\times R.$ $S = {(x, y) : y = x + 1 \;and \;0 < x < 2}, T = {(x, y) : x - y\; is\; an\; integer}$. Which one of the following is true?

asked Nov 29, 2018 by pady_1

0 answers

Let $L$ be the line of intersection of the planes $2x + 3y + z = 1$ and $x + 3y + 2z = 2$. If $L$ makes an angle $\alpha$ with the positive $x-axis$, then $\cos \alpha $ equals :

asked Nov 29, 2018 by pady_1

0 answers

A mass of M kg is suspened by a weightless string. The horizontal force that is required to displace it until the string makes an angle of $45^{\circ}$ with the initial vertical direction is :

asked Nov 13, 2018 by pady_1

0 answers

The differential equation representing the family of curves $y^2 = 2c (x + \sqrt{c})$, where $c > 0$, is a parameter, is of order and degree as follows:

asked Nov 5, 2018 by pady_1

0 answers

A particle is moving eastwards with a velocity of $5\; ms^{-1}$. In $10 \;s$ the velocity changes to $5\;ms^{-1}$ northwardas. The average acceleration in this time is:

asked Nov 5, 2018 by pady_1

0 answers

Let two numbers have arithmetic mean 9 and geometric mean 4. Then these numbers are the roots of the quadratic equation-

asked Nov 5, 2018 by pady_1

0 answers

A metallic rod of mass per unit length $0.5 \; kg \; m^{-1}$ is lying horizontally on a smooth inclined plane which makes an angle of $30^o$ with the horizontal. The rod is not allowed to slide down by flowing a current through it when a magnetic field of induction 0.25 T is acting on it in the vertical direction. The current flowing in the rod to keep it stationary is

asked Aug 21, 2018 by pady_1

1 answer

Concentration of the $Ag^+$ ions in a saturated solution of $Ag_2C_2O_4$ is $2.2 \times 10^{-4} \; mol\; L^{-1}$. Solubility product of $Ag_2C_2 O_4$ is :

asked Aug 21, 2018 by pady_1

1 answer

At $100^oC$ the vapour pressure of a solution of $6.5 \;g$ of a solute in $100\; g$ water is $732\; mm$. If $K_b = 0.52$, the boiling point of this solution will be:

asked Aug 21, 2018 by pady_1

1 answer

On heating which of the following releases $CO_2$ most easily ?

asked Aug 21, 2018 by pady_1

1 answer

A solid cylinder of mass 50 kg and radius 0.5 m is free to rotate about horizontal axis. A massless string is wound round the cylinder with one end attached to it and other hanging freely. Tension in the string required to produce an angular acceleration of 2 revolutions $s^{–2}$

asked Aug 20, 2018 by pady_1

1 answer

A small object of uniform rolls up a curved surface with an initially velocity 'v'. It reaches upto a maximum height of $\frac{3v^2}{4g}$ with respect to the initial position. The object is -

asked Aug 20, 2018 by pady_1

1 answer

Two persons of masses 55 kg and 65kg respectively, are at the opposite ends of a boat. The length of the boat is 30. m and weighs 100 kg. The 55 kg man walks up to the 65 kg man and sits with him. If the boat is in still water the center of mass of the system shift by:

asked Aug 20, 2018 by pady_1

1 answer

A planet moving along an elliptical orbit is closest to the sun at a distance $r_1$ and farthest away at a distance of $r_2$. If $v_1$ and $v_2$ are the linear velocities at these points respectively, then the ratio $\frac{v_1}{v_2}$ is :

asked Aug 16, 2018 by pady_1

1 answer

A ray of light travelling in a transparent medium of refractive index µ, falls on a surface separating the medium from air at an angle of incidence of 45º. For which of the following value of µ the ray can undergo total internal reflection -

asked Jul 26, 2018 by pady_1

2 answers

A thin circular ring of mass M and radius R is rotating in a horizontal plane about an axis vertical to its plane with a constant angular velocity $\omega$, If two objects each mass m be attached gently to the opposite ends of a f diameter of the ring, the ring, will then rotate with an angular velocity :

asked Jul 26, 2018 by pady_1

1 answer

If M (A, Z), $M_p$ and $M_n$ denote the masses of the nucleus $^{A}_ {Z} X$ , proton and neutron respectively in units of u (1u = 931.5 Me$\frac{V}{C}^2$ ) and BE represents its bonding energy in MeV, then -

asked Jul 26, 2018 by pady_1

1 answer

The position $x$ of a particle with respect to time $t$ along x-axis is given by $x = 9t^2 – t^3$ where $x$ is in metres and $t$ in seconds. What will be the position of this particle when it achieves maximum speed along the + x direction ?

asked Jul 26, 2018 by pady_1

1 answer

A transistor-oscillator using a resonant circuit with an inductor L (of negligible resistance) and a capacitor C in series produce oscillations of frequency f. If L is doubled and C is changed to 4C, the frequency will be:-

asked Jul 25, 2018 by pady_1

1 answer

A 5-ampere fuse wire can withstand a maximum power of 1 watt in the circuit. The resistance of the fuse wire is :

asked Jul 24, 2018 by pady_1

1 answer

A car is moving towards a high cliff. The car driver sounds a horn of frequency 'f'. The reflected sound heard by the driver has a frequency 2f. If 'v' be the velocity of sound then the velocity of the car, in the same velocity units, will be -

asked Jul 24, 2018 by pady_1

2 answers

A man weighs 80 kg He stands on a weighing scale in a lift which is moving upwards with a uniform acceleration of $5m/s^2$. What would be the reading on the scale ? ($g = 10 m/s^2$)

asked Jul 24, 2018 by pady_1

2 answers

If particles are moving with same velocity, then De-Broglie wavelength is maximum for : -

asked Jul 23, 2018 by pady_1

1 answer

A child is sitting on a swing. Its minimum and maximum heights from the ground is 0.75 m and 2 m respectively, its maximum speed will be

asked Jul 20, 2018 by pady_1

1 answer

A man is slipping on a frictionless inclined plane & a bag falls down from the same height. Then the speed of both is related as :

asked Jul 20, 2018 by pady_1

1 answer