Recent questions tagged 33

Which of the following series of transitions in the spectrum of hydrogen atom falls in visible region ?

asked Jul 8, 2019 by pady_1

2 answers

The null points are on the equatorial line of a bar magnet when the north pole of the magnet is pointing :

asked Dec 19, 2018 by pady_1

0 answers

The least distance of distinct vision is 25 cm. If the focal length of convex lens is 10 cm, it acts as a simple microscope of maximum magnification :

asked Dec 19, 2018 by pady_1

0 answers

A wheel has a speed of $1200$ revolution per minute and is made to slow down at a rate of $4\; radian/sec^2$. The number of revolutions it makes before coming to rest is :

asked Dec 19, 2018 by pady_1

0 answers

An electron moes with speed $2 \times 10^5\; m/s$ along the positive $x$-direction in the presence of a magnetic field of induction $\overrightarrow{B} = \hat{i} + 4 \hat{j} - 3 \hat{k}$ (in tesla). The magnitude of the force experienced by the electron in newtons is : (Charge on the electron =$1.6 \times 10^{-19}C$)

asked Dec 11, 2018 by pady_1

0 answers

By increasing the temperature, the specific resistance of a conductor and a semiconductor :

asked Dec 11, 2018 by pady_1

0 answers

A wire suspended vertically from one of its ends is stretched by attaching a weight of 200 N to the lower end. The weight stretches the wire by 1 mm. Then the elastic energy stored in the wire is :

asked Dec 11, 2018 by pady_1

0 answers

If $\alpha, \; \beta \in C$ are the distinct roots, of the equation $x^2 - x + 1 = 0$, then $\alpha^{101} + \beta^{107} $ is equal to :

asked Dec 11, 2018 by pady_1

1 answer

An electron bean is acceleration by a potential difference $V$ to hit a metallic target to produce X-rays. It produces continuous as well as characteristic X-rays. If $\lambda_{min}$ is the smallest possible wavelength of X-ray in the spectrum, the variation of log $\lambda_{min}$ with $\log\; V$ is correctly represented in :

asked Dec 11, 2018 by pady_1

0 answers

A stream of electrons from a heated filament was passed between two charged plates kept at a potential difference $V$ esu. If $e$ and $m$ are charge and mass of an electron, respectively, then the value of $h/ \lambda$ (where $\lambda$ is wavelength associated with electron wave) is given by :

asked Dec 11, 2018 by pady_1

0 answers

If the principal quantum number n56, the correct sequence of filling of electrons will be :

asked Dec 11, 2018 by pady_1

0 answers

If $a \in R$ and the equation $-3(x - [x])^2 + 2 (x - [x]) + a^2 = 0$ (where $[x]$ denotes the greatest integer $\leq x$) has no integral solution, then all possible values of a lie in the interval

asked Dec 11, 2018 by pady_1

1 answer

Given : A circle, $2x^2 + 2y^2 = 5 $ and a parabola. $y^2 = 4 \sqrt{5} x$. Statement - I : An equation of a common tangent to these curves is $y = x+\sqrt{5}$. Statement - II : If the line, $y = mx + \frac{\sqrt{5}}{m} (m \neq 0)$is their common tangent, then m satisfies $m^4 - 3m^2 +2 = $

asked Dec 11, 2018 by pady_1

1 answer

In a uniformly charged sphere of total charge Q and radius R, the electric field E is plotted as a function of distance from the centre. The graph which would correspond to the above will be

asked Dec 11, 2018 by pady_1

0 answers

The coefficient of $x^7$ in the expansion of $(1 - x - x^2 + x^3)^6$ is

asked Dec 11, 2018 by pady_1

0 answers

Statement-1 : Two particles moving in the same direction do not lose all their energy in a completely inelastic collision. Statement-2 : Principle of conservation of momentum holds true for all kinds of collisions.

asked Dec 11, 2018 by pady_1

0 answers

Arrange the carbanions, $(CH_3)_3 \overline{C}, \;\overline{C}Cl_3, (CH_3)_2 \overline{C}H, \;C_6H_5 \overline{C}H_2,$ in order of thier decreasing stability :

asked Nov 29, 2018 by pady_1

0 answers

27. Let a, b, c be any real numbers. Suppose that there are real numbers x, y, z not all zero such that x = cy + bz, y = az + cx and z = bx + ay. Then $a^2 + b^2 + c^2 + 2abc$ is equal to

asked Nov 29, 2018 by pady_1

0 answers

If one of the lines of $my^2 + (1 - m^2) xy - mx^2 = 0 $ is a bisector of the angle between the lines $xy = 0$, then $m$ is :

asked Nov 29, 2018 by pady_1

0 answers

If the ratio of the concentration of electrons to that of holes in a semiconductor is $\frac{7}{5}$ and the ratio of currents is $\frac{7}{4}$, then what is the ratio of their drift velocities ?

asked Nov 13, 2018 by pady_1

0 answers

A function is matched below against an interval where it is supposed to be increasing. Which of the following pairs is incorrectly matched ?

asked Nov 5, 2018 by pady_1

0 answers

The temperature-entropy diagram of a reversible engine cycle is given in the figure. Its efficiency is :

asked Nov 5, 2018 by pady_1

0 answers

The normal to the curve $x = a (1+ \cos \theta)\; y = a \; sin \theta$ at $'\theta'$ always passes through the fixed point

asked Nov 5, 2018 by pady_1

0 answers

A student measured the diameter of a small steel ball using a screw gauge of least count 0.001 cm. The main scale reading is 5 mm and zero of circular scale division coincides with 25 divisions above the reference level. If screw gauge has a zero error of -0.004 cm, the correct diameter of the ball is

asked Aug 21, 2018 by pady_1

1 answer

A gas is allowed to expand in a well insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy $\Delta U$ of the gas in joules will be -

asked Aug 21, 2018 by pady_1

1 answer

In the correct $X - C \equiv CH \xrightarrow[\text{(2) $CH_3CH_2Br$}]{\text{(1) $NaNH_2 / liq. NH_3$}} X \xrightarrow[\text{(2) $CH_3CH_2Br$}]{\text{$(1) NaNH_2 / liq.NH_3$}}$ X and Y are:

asked Aug 21, 2018 by pady_1

1 answer

Which one of the following esters gets hydrolysed most easily under alkaline conditions -

asked Aug 21, 2018 by pady_1

1 answer

A transformer having efficiency of 90% is working on 200 V and 3 kW power supply. If the current in the secondary coil is 6 A the voltage across the secondary coil and the current in the primary coil respectively are:

asked Aug 20, 2018 by pady_1

1 answer

The condition under which a microwave oven heats up a food item containing water molecules most efficiently is -

asked Aug 20, 2018 by pady_1

1 answer

Two similar coils of radius R are lying concentrically with their planes at right angles to each other.The currents flowing in them are I and 2I, respectively. The resultant magnetic field induction at the centre will be

asked Aug 20, 2018 by pady_1

1 answer

Out of the following functions representing motion of a particle which represents SHM : (A) $y = \sin \omega t - \cos \omega t $ (B) $ y = \sin^3 \omega t $ (C) $ y = 5 \cos (\frac{3 \pi}{4} - 3 \omega t)$ (D) $ y = 1 + \omega t + \omega^2 t^2$

asked Aug 16, 2018 by pady_1

1 answer

A man of 50 kg mass is standing in a gravity free space at a height of 10 m above the floor. He throws a stone of 0.5 kg mass downwards with a speed 2 m/s. When the stone reaches the floor, the distance of the man above the floor will be –

asked Jul 26, 2018 by pady_1

1 answer

Under the influence of a uniform magnetic field, a charged particle moves with constant speed V in a circle of radius R. The time period of rotation of the particle :

asked Jul 26, 2018 by pady_1

1 answer

Curie temperature is the temperature above which -

asked Jul 26, 2018 by pady_1

1 answer

A charged particle (charge q) is moving in a circle of radius R with uniform speed v. The associated magnetic moment $\mu$ is given by:

asked Jul 26, 2018 by pady_1

1 answer

The molar specific heat at constant pressure of an ideal gas is $[\frac 7 2]R$. The ratio of specific heat at constant pressure to that at constant volume is:-

asked Jul 25, 2018 by pady_1

1 answer

A drum of radius R and mass M, rolls down without slipping along an inclined plane of angle ?. The frictional force-

asked Jul 24, 2018 by pady_1

1 answer

The phase difference between two waves, $y_{1}=10^{-6} \sin \{100t+(x/50)+0.5\}m$ $y_2=10^{-6} \cos \{100t+(\frac{ x} {50})\}m$ Where X is expressed in metres and t is expressed in seconds, is approximately : -

asked Jul 24, 2018 by pady_1

1 answer

Solar energy is mainly caused due to :

asked Jul 24, 2018 by pady_1

1 answer

A whistle revolves in a circle with angular speed $\omega$ = 20 rad/sec using a string of length 50 cm. If the frequency of sound from the whistle is 385 Hz, then what is the minimum frequency heard by an observer which is far away from the centre : - ($V_{sound }= 340 m/s$)

asked Jul 23, 2018 by pady_1

1 answer

A disc is rolling the velocity of its centre of mass is $V_cm$ then which one will be correct :-

asked Jul 20, 2018 by pady_1

1 answer

The bob of simple pendulum having length l, is displaced from mean position to an angular position $\theta$ with respect to vertical. If it is released, then velocity of bob at lowest position :

asked Jul 20, 2018 by pady_1

1 answer

For the diffraction from a crystal with $\lambda$ = 1Å and Bragg's angle $\theta$ = 60°, then for the second order diffraction 'd' will be :

asked Jun 15, 2018 by pady_1

1 answer

Which of the following letters does not have the vertical line of symmetry?

asked Dec 31, 2015 by pady_1

1 answer

Tori's lounge is 8 metres wide and 8 metres long. She wants to install red carpet that costs ₹328.00 per square metre. How much will it cost to buy enough carpet for the lounge?

asked Dec 31, 2015 by pady_1

0 answers

A factory makes 11596 shirts every week. How many items are manufactured in $\large\frac{23}{26}$ year?

asked Dec 31, 2015 by pady_1

0 answers

What \% is 86 of 2580?

asked Dec 31, 2015 by pady_1

0 answers

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