Recent questions tagged 14

Conjugate base for Bronsted acids $H_2O$ and HF are:-

asked Jul 8, 2019 by pady_1

1 answer

For an electron circulating around the nucleus, the centripetal force is supplied by :

asked Dec 19, 2018 by pady_1

0 answers

The minimum speed for a particle at the lowest point of a vertical circle of radius $R$, to describe the circle is $v$. If the radius of circle is reduced to one-fourth its value, the corresponding minimum speed will be :

asked Dec 19, 2018 by pady_1

0 answers

The $X$-ray wavelength of $L_a$ line of platinum $(Z = 78)$ is $1.30 \mathring{A}$. The $X$-ray wavelenght of $L_a$ line of molybdenum $(Z =42)$ is :

asked Dec 19, 2018 by pady_1

0 answers

The sound waves of wavelengths 5 m and 6 m formed 30 beats in 3 seconds. The velocity of sound is :

asked Dec 11, 2018 by pady_1

0 answers

On moving a charge of 20 C by 2 cm, 2J of work is done, then the potential difference between the points is :

asked Dec 11, 2018 by pady_1

0 answers

A circular disc $X$ of radius $R$ is made from an iron plate of thickess $t$, and another disc $Y$ of radius $4R$ is made from an iron plate of thickness $t/4$. Then the relation between the moment of inertia $I_X$ and $I_Y$ is :

asked Dec 11, 2018 by pady_1

0 answers

A telephonic communication service is working at carrier frequency of 10 GHz. Only 10% of it is utilized for transmission. How many telephonic channels can be transmitted simultaneously if each channel requires a bandwidth of 5 kHz?

asked Dec 11, 2018 by pady_1

0 answers

For any three positive real numbers $a, \;b$ and $c,\; 9(25a^2 + b^2 ) + 25(c^2 – 3ac) = 15b(3a + c)$, Then

asked Dec 11, 2018 by pady_1

1 answer

The temperature dependence of resistances of Cu and undoped Si in the temperature range 300-400 K, is best described by :

asked Dec 11, 2018 by pady_1

0 answers

A thin disc of radius $b=2a$ has a concentric hole of radius $'a'$ in it (see figure). It carries uniform surface charge $'\sigma'$ on it. If the electric field on its axis at height $'h (h<< a)$ from its centre is given as 'Ch' then value of 'C' is :

asked Dec 11, 2018 by pady_1

0 answers

During the propagation of electromagnetic waves in a medium:

asked Dec 11, 2018 by pady_1

0 answers

Given $E^0_{Cr^{3+}/Cr} = -0.74 \; V; \; E^0_{MnO_4^-/Mn^{2+}} = 1.51 \; V$ $E^0_{Cr_2O_7^{2-} / Cr^{3+}} = 1.33\; V; \;E^0_{Cl/Cl^-} = 1.36\; V$ Based on the data given abov, strongest oxidising agent will be :

asked Dec 11, 2018 by pady_1

0 answers

Let $x_1, x_2, ....., x_n$ be $n$ observations, and let $\overline{x}$ be their arithematic mean and $\sigma^2$ be their variance. Statement 1 : Variance of $2x_1, 2x_2, ....,2x_n$ is $4 \sigma^2$ Statement 2 : Arithmetic mean of $2x, 2x_2, .... , 2x_n$ is $4 \overline{x}$.

asked Dec 11, 2018 by pady_1

1 answer

A thermally insulated vessel contains an ideal gas of molecular mass M and ratio of specific heats $\gamma$. It is moving with speed $v$ and is suddenly brought to rest. Assuming no heat is lost to the surroundings, its temperature increases by :

asked Dec 11, 2018 by pady_1

0 answers

Which one of the following has an optical isomer ?

asked Dec 11, 2018 by pady_1

0 answers

A mixture of light, consisting of wavelength 590 nm and an unknown wavelength , illuminates Young's double slit and gives rise to two overlapping interference patterns on the screen. The central maximum of both lights coincide. Further, it is observed that the third bright fringe of known light coincides with the $4^{th}$ bright fringe of the unknown light. From this data, the wavelength of the unknown light is

asked Nov 29, 2018 by pady_1

0 answers

The non-zero verctors $\overrightarrow{a}$ , $\overrightarrow{b}$ and $\overrightarrow{c}$ are related by $\overrightarrow{a} =8\overrightarrow{b} and \overrightarrow{c} = -7 \overrightarrow{b}$ .Then the angle between $\overrightarrow{a}$ and $\overrightarrow{c}$ is

asked Nov 29, 2018 by pady_1

0 answers

The normal to a curve at $P(x,y)$ meets the $x-axis$ at $G$. If the distance of $G$ from the origin is twice the abscissa of $P$, then the curve is a :

asked Nov 29, 2018 by pady_1

0 answers

Which of the following units denotes the dimensions $[ML^2/Q^2]$, where $Q$ denotes the electric charge ?

asked Nov 13, 2018 by pady_1

0 answers

The value of $^{50}C_4 $ $\displaystyle\sum_{r = 1}^{6}$ $^{56-r}C_3$ is :

asked Nov 5, 2018 by pady_1

0 answers

The moment of inertia of uniform semicircular disc of mass M and radius r about a line perpendicular to the plane of the disc through the centre is :

asked Nov 5, 2018 by pady_1

0 answers

The one root of the equation $x^2 + px + 12 = 0$ is 4, while the equation $x^2+px+q=0$ has equal roots, then the value of 'q' is

asked Nov 5, 2018 by pady_1

0 answers

The magnetic potential energy stored in a certain inductor is 25 mJ, when the current in the inductor is 60 mA. This inductor is of inductance

asked Aug 21, 2018 by pady_1

1 answer

Pick out the correct statement with respect to $[Mn(CN)_6]^{3-}$

asked Aug 21, 2018 by pady_1

1 answer

In a protein molecule various amino acids are linked together by:

asked Aug 21, 2018 by pady_1

1 answer

In the reaction with HCl, an alkene reacts in accordance with the Markovnikov's rule, to give a product 1-chloro-1- methylcyclohexane. The possible alkene is :

asked Aug 21, 2018 by pady_1

1 answer

A certain number of spherical drops of a liquid of radius 'r' coalesce to form a single drop of radius 'R' and volume 'V'. If 'T' is the surface tension of the liquid then:

asked Aug 20, 2018 by pady_1

1 answer

The molar specific heats of an ideal gas at constant pressure and volume are denoted by $C_p$ and $C_v$, respectively. If $\gamma = \frac{C_p}{C_v}$ and R is the universal gas constant, then $C_v$ is equal to -

asked Aug 20, 2018 by pady_1

1 answer

The height at which the weight of a body becomes $\frac{1}{16}$th , its weight on the surface of earth (radius R), is

asked Aug 20, 2018 by pady_1

1 answer

Force F on a particle moving in a straight line varies with distance d as shown in the figure. The work done on the particle during its displacement of 12 m is :

asked Aug 16, 2018 by pady_1

1 answer

A particle has initial velocity (3i + 4j) and has acceleration (0.4i + 0.3j).Its speed after 10 s is –

asked Jul 26, 2018 by pady_1

1 answer

A body of mass 1 kg of thrown upwards with a velocity 20 m/s. It momenetarily comes to rest after attaining a height of 18m. How much energy is lost due to air friction ? $(g=10m/s^{2})$

asked Jul 26, 2018 by pady_1

1 answer

The circuit is equivalent to

asked Jul 26, 2018 by pady_1

1 answer

Assuming the sun to have a spherical outer surface of radius $r$, radiating like a black body at temperature $t^{\circ}$C, the power received by a unit surface, (normal to the incident rays) at distance $R$ from the centre of the Sun is Where $\sigma$ is the Stefan's Contant :-

asked Jul 26, 2018 by pady_1

1 answer

For angles of projection of a projectile at angles $(45 ^\circ-\theta)$ and$(45 ^\circ+\theta)$, the horizontal ranges described by the projectile are in the ratio of:

asked Jul 25, 2018 by pady_1

1 answer

When a wire of uniform cross-section a, length l and resistance R is bent into a complete circle, resistance between any two of diametrically opposite points will be -

asked Jul 24, 2018 by pady_1

1 answer

A stone is tied to a string of length 'l' and is whirled in a vertical circle with the other end of the string as the centre. At a certain instant of time, the stone is at its lowest position and has a speed 'u'. The magnitude of the change in velocity as it reaches a position where the string is horizontal (g being acceleration due to gravity) is :-

asked Jul 24, 2018 by pady_1

1 answer

A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will

asked Jul 24, 2018 by pady_1

2 answers

Diameter of human eye lens is 2 mm. What will be the minimum distance between two points to resolve them, which are situated at a distance of 50 meter from eye. The wavelength of light is 5000 Å :-

asked Jul 23, 2018 by pady_1

1 answer

$X(n, \alpha)$ $^7_3Li$, then X will be :-

asked Jul 20, 2018 by pady_1

1 answer

By photo electric effect, Einstein proved :

asked Jul 20, 2018 by pady_1

0 answers

A coil of one loop is made from a wire of length L and thereafter a coil of two loops is made from same wire, then the ratio of magnetic field at the centre of coils will be :

asked Jun 15, 2018 by pady_1

1 answer

The number of days left in the month of September are one fifth of the number of days already passed. How many days are left in the month ?

asked Dec 31, 2015 by pady_1

1 answer

Which type of graph would you use to show the price of a stick of butter over the past 50 years?

asked Dec 31, 2015 by pady_1

0 answers

Find the area of a square of side 40 cm.

asked Dec 31, 2015 by pady_1

0 answers

$2\large\frac{1}{2} \times \large\frac{1}{3}$

asked Dec 31, 2015 by pady_1

0 answers

What \% is 43 of 172?

asked Dec 31, 2015 by pady_1

0 answers

The statement: 5 divides 20 if 5 divides -20, in if-then form would be

asked Jan 20, 2014 by thanvigandhi_1

1 answer

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