Recent questions tagged 18

Which of the following species is not stable ?

asked Jul 8, 2019 by pady_1

1 answer

Neglecting gravity, the potential energy of a molecule of a liquid on the surface of the liquid when compared to the potential energy of a molecule inside the liquid is :

asked Dec 19, 2018 by pady_1

0 answers

If $R$ is the radius of earth, the height, at which the weight of a body becomes $\frac{1}{4}$ of its weight on the surface of earth, is :

asked Dec 19, 2018 by pady_1

0 answers

In Bohr model of hydrogen atom, the ratio of period of revolutionn of an electron in $n=2$ and $n=1$ orbit is :

asked Dec 19, 2018 by pady_1

0 answers

A lead bullet of mass $10\; g$ travelling at $300\; m/s$ strikes against a block of wood and comes to rest. Assuming $50 \%$ of heat is absorbed by the bullet, the increase in its temperature is : (specific heat of lead = $150 \; J/kg ^{\circ} C$ )

asked Dec 11, 2018 by pady_1

0 answers

A charged particle $q$ is placed at the centre $O$ of cube of length $L \;(ABCDEFGH)$. Another same charge $q$ is placed at a distance $L$ from $O$. Then the electric flux through $ABCD$ is :

asked Dec 11, 2018 by pady_1

0 answers

When $U^{238}$ nucleus originally at rest, decays by emitting an alpha particle having a speed $u$, the recoil speed of the residual nucleus is :

asked Dec 11, 2018 by pady_1

0 answers

Three concentric metal shells A, B and C of respective radii a, b and c (a < b < c) have surface charge densities $+\sigma, \; -\sigma$ and $+\sigma$ respectively. The potential of shell B is :

asked Dec 11, 2018 by pady_1

0 answers

A hyperbola passes through the point $P(\sqrt{2}, \sqrt{3})$ and has foci at $(\pm 2, 0)$. Then the tangent to this hyperbola at $P$ also passes through the point :

asked Dec 11, 2018 by pady_1

1 answer

Arrange the following electromagnetic radiations per quantum in the order of increasing energy : A : Blue light B : Yellow light C : X-ray D : Radiowave.

asked Dec 11, 2018 by pady_1

0 answers

A $10V$ battery with internal resistance $1 \Omega$ and a $15V$ battery with internal resistance $0.6 \Omega$ are connected in parallel to a voltmeter (see figure). The reading in the voltmeter will be close to :

asked Dec 11, 2018 by pady_1

0 answers

From a tower of height H, a particle is thrown vertically upwards with a speed u. The time taken by the particle, to hit the ground, is n times that taken by it to reach the highest point of its path. The relation between H, u and n is:

asked Dec 11, 2018 by pady_1

0 answers

Which of the following complex species is not expected to exhibit optical isomerism ?

asked Dec 11, 2018 by pady_1

0 answers

Assuming the balls to be identical except for difference in colours, the number of ways in which one or more balls can be selected from 10 white, 9 green and 7 black balls is

asked Dec 11, 2018 by pady_1

0 answers

Three perfect gases at absolute temperature $T_1, T_2, T_3$ are mixed. The masses of molecules are $m_1, m_2$ and $m_3$ and the number of molecules are $n_1, n_2$ and $n_3$ respectively. Assuming no loss of energy, the final temperature of the mixture is :

asked Dec 11, 2018 by pady_1

0 answers

In aqueous solution the ionization constants for carbonic acid area $K_1=4.2 \times 10^{-}$ and $K_2=4.8 \times 10^{-11}$ Select the correct statement for a saturated 0.034 M solution of the carbonic acid.

asked Dec 11, 2018 by pady_1

0 answers

A motor cycle starts from rest and acceleration along a straight path at $2\; m/s^2$. At the starting point of the motor cycle there is a stationary electric sire. How far has the motor cycle gone when the driver hears the frequency of the siren at 94% of its value when the motor cycle was at rest ? (speed of sound = 330 $ms^{-1}$ )$

asked Nov 29, 2018 by pady_1

0 answers

Let A be a $2 \times 2$ matrix with real entries. Let I be the $2 \times 2$ identity matrix. Denote by tr (A), the sum of diagonal entries of A. Assume that $A^2 = I$. Statement -1: If $A \neq I$ and $A \neq - I$, then det A = - 1. , Statement -2: If $A \neq I$ and $A \neq - I$, then $tr (A) \neq 0$.

asked Nov 29, 2018 by pady_1

0 answers

If $D = \begin{vmatrix} 1 & 1 & 1 \\ 1 & 1+x & 1 \\ 1 & 1 & 1+y \end{vmatrix}$ for $x \neq 0, y \neq 0$, then $D$ is :

asked Nov 29, 2018 by pady_1

0 answers

A player caught a cricket ball of mass 150 g moving at a rate of 20 m/s. If the catching process is completed in 0.1 s, the force of the blow exerted by the ball on the hand of the player is equal to :

asked Nov 13, 2018 by pady_1

0 answers

If $z_1$ and $z_2$ are two non-zero complex numbers such that $|z_1+z_2| = |z_1| + |z_2|$, then arg $z_1$ - arg $z_2$ is equal to :

asked Nov 5, 2018 by pady_1

1 answer

A 20 cm long capillary tube is dipped in water. The water rises upto 8 cm. If the entire arrangement is put in a freely falling elevator, the length of water column in the capillary tube will be :

asked Nov 5, 2018 by pady_1

0 answers

Let $T_f$ be the $r^{th}$ term of an A.P whose first term is a and common difference is $d$. If for some positive integers $m, \;n, \;m \neq n, \;T_m = \frac{1}{n}$ and $T_n = \frac{1}{m}$, then $a-d$ equals

asked Nov 5, 2018 by pady_1

0 answers

In the combination of the following gates the output Y can be written in terms of inputs A and B as

asked Aug 21, 2018 by pady_1

1 answer

It is because of inability of $ns^2$ electrons of the valence shell to participate in bonding that :

asked Aug 21, 2018 by pady_1

1 answer

The pair of electron in the given carbanion, $CH_3 C \equiv C^{\Theta}$, is present in which of the following orbitals ?

asked Aug 21, 2018 by pady_1

1 answer

Which of the statements given below is incorrect ?

asked Aug 21, 2018 by pady_1

0 answers

A thermodynamics system undergoes cyclic process ABCDA as shown in Fig. The work done by the system in the cycle is:

asked Aug 20, 2018 by pady_1

1 answer

In the given $(V-T)$ diagram, what is the relation between pressures $P_1$ and $P_2$ ?

asked Aug 20, 2018 by pady_1

1 answer

A thermodynamics system is taken trough the cycle ABCD as shown in figure. Heat rejected by the gas during the cycle is :

asked Aug 20, 2018 by pady_1

1 answer

If power dissipated in the $9 \Omega$ resistor in the circuit shown is 36 Watt, the potential difference across the $2 \Omega$ resistor is :

asked Aug 16, 2018 by pady_1

1 answer

A particle moves a distance x in time t according to equation x = $(t + 5)^–1$. The acceleration of particle is proportional to –

asked Jul 26, 2018 by pady_1

1 answer

The internal energy change in a system that has absorbed 2 k cal of heat and done 500 J of work is :

asked Jul 26, 2018 by pady_1

1 answer

Two periodic waves of intensities $I_1$ and $I_2$ pass through a region at the same time in the same direction. the sum of the maximum and minimum intensities is -

asked Jul 26, 2018 by pady_1

1 answer

The phase difference between the instantaneous velocity and acceleration of a particle executing simple harmonic motion is :-

asked Jul 26, 2018 by pady_1

1 answer

A microscope is focused on a mark on a piece of paper and then a slab of glass of thickness 3 cm and refractive index 1.5 is placed over the mark. How should the microscope be moved to get the mark in focus again:-

asked Jul 25, 2018 by pady_1

1 answer

If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material are denoted by $\mu_d$, $\mu_p$ and $\mu_f$ respectively, then

asked Jul 24, 2018 by pady_1

2 answers

If in a nuclear fusion process the masses of the fusing nuclei be $m_1$ and $m_2$ and the mass of the resultant nucleus be$ m_3$, then

asked Jul 24, 2018 by pady_1

2 answers

In case of a forced vibration, the resonance wave becomes very sharp when the :

asked Jul 24, 2018 by pady_1

1 answer

For a black body at temperature 727ºC, its radiating power is 60 watt and temperature of surrounding is 227ºC. If temperature of black body is changed to 1227ºC then its radiating power will be : -

asked Jul 23, 2018 by pady_1

1 answer

If the tension and diameter of a sonometer wire of fundamental frequency n is doubled and density is halved then its fundamental frequency will become

asked Jul 20, 2018 by pady_1

3 answers

The frequency order of for $\gamma$- rays b, X – rays a, UV – rays(c):

asked Jul 20, 2018 by pady_1

1 answer

One part of a device is connected with the negative terminal of a battery and another part is connected with the positive terminal of a battery. If their ends now altered, current does not flow in circuit, then the device will be :

asked Jun 15, 2018 by pady_1

0 answers

Pick the odd one out : SNAKE, WHALE, CROCODILE, SIMMER

asked Dec 31, 2015 by pady_1

1 answer

The chart shows production of different vegetables in a farm. If production of tomato was 11500 Kg, find the production of Potato.

asked Dec 31, 2015 by pady_1

0 answers

Calculate the area of a square patch of grass of side 16 cm.

asked Dec 31, 2015 by pady_1

0 answers

The parking lot of the Mall has a capacity of 792 cars. On Wednesdays the ratio of occupied spots to empty spots in the parking lot was 3:19. The number of additional cars that could park there is

asked Dec 31, 2015 by pady_1

1 answer

What \% is 60 of 150?

asked Dec 31, 2015 by pady_1

0 answers

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