Recent questions tagged 39

The non-essential amino acid among the following is :

asked Jul 8, 2019 by pady_1

1 answer

If a long hollow copper pipe carries a current, the magnetic field produced will be :

asked Dec 19, 2018 by pady_1

0 answers

Two charges $8C$ and $-6C$ are placed at a distance of separation $d$ between them and exerts a force of magnitude $F$ on each other. If a charge $8C$ is added to each of these and they are brought nearer to by a distance $d/3$, the magnitude of force between them will be :

asked Dec 19, 2018 by pady_1

0 answers

8000 identical water drops are combined to form a big drop. The the ratio of final surface energy to the initial surface energy of all the drops together is :

asked Dec 19, 2018 by pady_1

0 answers

A body of weight $''64 N''$ is pushed with just enough force to start it moving across a horizontal floor and the same force continues to act afterwards. If the coefficients of static and dynamic friction are 0.6 and 0.4 respectively, the acceleration of the body is : (acceleration due to gravity = g)

asked Dec 11, 2018 by pady_1

0 answers

An astronomical telescope has a large aperture to `:

asked Dec 11, 2018 by pady_1

0 answers

The displacement y of a wave travelling in the $x$-direction is given by $y = 10^{-4} \sin (600 t - 2x + \frac{x}{3})$ metre, where, $x$ is epressed in metres and $t$ in seconds. The speed of the wave-motion, in $ms^{-1}$ is :

asked Dec 11, 2018 by pady_1

0 answers

A bag contains 4 red and 6 black balls. A ball is drawn at random from the bag, its colour is observed and this ball along with two additional balls of the same colour are returned to the bag. If now a ball is drawn at random from the bag, then the probability that this drawn ball is red, is

asked Dec 11, 2018 by pady_1

2 answers

The temperature of an open room of volume $30 \;m^3$ increased from $17^{\circ}C$ to $27^{\circ}C$ due to the sunshine. The atmospheric pressure in the room remains $1 \times 10^5 \; Pa$. If $n_i$ and $n_f$ are the number of molecules in the room before and after heating, then $n_f – n_i$ will be :

asked Dec 11, 2018 by pady_1

0 answers

Decomposition of $H_2O_2$ follows a first order reaction. In fifty minutes the concentration of $H_2O_2$ decreases from $0.5$ to $0.125\; M$ in one such decomposition. When the concentration of $H_2O_2$ reaches $0.05\; M$, the rate of formation of $O_2$ will be :

asked Dec 11, 2018 by pady_1

0 answers

The reaction $2N_2O_5 (g) \to 4NO_2 (g) +O_2 (g)$ follows first order kinetics. The pressure of a vessel containing only $N_2O_5$ was found to increase from $50\; mm \;Hg$ to $87.5\; mm \;Hg$ in $30\; min$. The pressure exerted by the gases after $60 \;min$. will be (Assume temperature remains constant) :

asked Dec 11, 2018 by pady_1

0 answers

If A is an $3 \times 3$ non-singular matrix such that $AA' = A'A$ and $B = A^{-1}A'$, then $BB'$ equals

asked Dec 11, 2018 by pady_1

1 answer

The x-coordinate of the incentre of the triangle that has the coordinates of mid points of its sides as (0, 1), (1, 1) and (1, 0) is

asked Dec 11, 2018 by pady_1

1 answer

Helium gas goes through a cycle ABCDA (consisting of two isochoric and two isobaric lines) as shown in figure. Efficiency of this cycle is nearly : (Assume the gas to be close to ideal gas )

asked Dec 11, 2018 by pady_1

1 answer

The value of $\begin{align} \int_0^1 \frac{8 \log (1+x)}{1+x^2} dx \end{align} $ is

asked Dec 11, 2018 by pady_1

0 answers

The figure shows the position â€“ time (x â€“ t) graph of one-dimensional motion of a body of mass 0.4 kg. The magnitude of each impulse is

asked Dec 11, 2018 by pady_1

0 answers

In an atom, an electron is moving with a speed of 600 m/s with an accuracy of $0.005 \%$. Certainity with which the position of the electron can be located is ($h = 6.6 \times 10^{-34} \; kg \; m^2\; s^{-1}$, mass of electron, $e_m = 9.1 \times 10^{-31} kg$)

asked Nov 29, 2018 by pady_1

0 answers

Identify the wrong statements in the following:

asked Nov 29, 2018 by pady_1

0 answers

The area enclosed between the curves $y^2 = x$ and $ y = |x|$ is :

asked Nov 29, 2018 by pady_1

0 answers

The anode voltage of a photocell is kept fixed. The wavelength $\lambda$ of the light falling on the cathode is gradually changed. The plate current $I$ of the photocell varies as follows :

asked Nov 13, 2018 by pady_1

0 answers

Let $f:R \to R$ be a differentiable function having $f(2) = 6, f'(2) =(\frac{1}{48}) $. Then $\displaystyle\lim_{x \to 2} \int_6^{f(x)} \frac{4t^3}{x-2} dt$ equals :

asked Nov 5, 2018 by pady_1

0 answers

A fish looking up through the water sees the outside world, contained in a circular horizon. If the refractive index of water is $\frac{4}{3}$ and the fish is 12 cm below the water surface, the radius of this circle in cm is :

asked Nov 5, 2018 by pady_1

0 answers

The value of $\begin{align} I = \int_0^{\pi/2} \frac{(\sin x + \cos x )^2}{\sqrt{1+\sin 2x}} \;dx \end{align}$ is

asked Nov 5, 2018 by pady_1

0 answers

A sample of 0.1 g of water at $100^oC$ and normal pressure ($1.013 \times 10^5 Nm^{-2}$) requires 54 cal of heat energy to convert to steam at $100^oC$. If the volumn of the steam produced is 167.1 cc, the change in internal energy of the sample, is

asked Aug 21, 2018 by pady_1

1 answer

Which one of the following statements is not correct ?

asked Aug 21, 2018 by pady_1

1 answer

Which one given below is a non-reducing sugar ?

asked Aug 21, 2018 by pady_1

2 answers

What is the mass of the precipitate formed when 50 mL of 16.9% solution of $AgNO_3$ is mixed with 50 mL of 5.8% NaCl solution ? (Ag = 107.3, N = 14, O = 16, Na = 23, Cl = 35.5)

asked Aug 21, 2018 by pady_1

1 answer

When the energy of the incident radiation is increased by $20%$, the kinetic energy of the photoelectrons emitted from a metal surface increased from emitted 0.5 eV to 0.8eV. The work function of the metal is :

asked Aug 20, 2018 by pady_1

1 answer

A plano convex lens fits exactly into a plano concave lens. Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive indices $\mu_1$ and $\mu_2$ and R is the radius of curvature of the curved surface of the lenses, then the focal length of the combination is -

asked Aug 20, 2018 by pady_1

1 answer

An $\alpha$-particle moves in a circular path of radius 0.83 cm in the presence of a magnetic field of 0.25 $\frac{Wb}{m^2}$ . The de-Broglie wavelength associated with the particle will be

asked Aug 20, 2018 by pady_1

1 answer

In photoelectric emission process from a metal of work function 1.8 eV, the kinetic energy of most energetic electrons is 0.5 eV. The corresponding stopping potential is :

asked Aug 16, 2018 by pady_1

1 answer

A 220 volt input is supplied to a transformer. The output circuit draws a current of 2.0 ampere at 440 volts. If the efficiency of the transformer is 80%, the current drawn by the primary windings of the transformer is –

asked Jul 26, 2018 by pady_1

1 answer

The number of photoelectrons emitted for light of a frequency v (higher than the threshold frequency $v_0$) is proportional to :

asked Jul 26, 2018 by pady_1

1 answer

In an A.C. circuit the emf (e) and the current (i) at any instant are given respectively by : $e=E_0 \sin \omega t$ $i=I_0 \sin(\omega t-\phi)$ The average power in the circuit over one cycle of A.C. is -

asked Jul 26, 2018 by pady_1

2 answers

A 5 watt source emits monochromatic light of wavelength 5000 Å. When placed 0.5 m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of 1.0m, the number of photo electrons liberated will :

asked Jul 26, 2018 by pady_1

1 answer

The time of reverberation of a room A is one second. What will be the time (in seconds) of reverberation of a room, having all the dimensions double of those of room A-

asked Jul 25, 2018 by pady_1

1 answer

Which of the following circular rods, (given radius r and length l) each made of the same energy material and whose ends are maintained at the same temperature will conduct most heat

asked Jul 24, 2018 by pady_1

1 answer

If $\mid \overrightarrow{A}\times \overrightarrow{B}\mid=\sqrt{3} \overrightarrow{A}.\overrightarrow{B}$ then the value of $\mid \overrightarrow{A}+ \overrightarrow{B}\mid$ is:

asked Jul 24, 2018 by pady_1

1 answer

Reverse bias applied to a junction diode

asked Jul 24, 2018 by pady_1

1 answer

Some charge is being given to a conductor. Then its potential : -

asked Jul 23, 2018 by pady_1

1 answer

The equation of a wave is represented by $y = 10^{-4} \sin (100t - \frac{x}{10}) m$, then the velocity of wave will be :-

asked Jul 20, 2018 by pady_1

1 answer

A car battery of emf 12 V and internal resistance $5\times10^{-2}\Omega$, receives a current of 60 Å from external source, then terminal voltage of battery is :

asked Jul 20, 2018 by pady_1

1 answer

In the Bohr model of H-atom, an electron (e) is revolving around a proton (p) with velocity v, if r is the radius of orbit and m is mass and $\varepsilon_{0}$ is vacuum permittivity, the value of v is :

asked Jun 15, 2018 by pady_1

1 answer

The adventure club went on a hike to see a waterfall. To get to the hike, the club members took 5 cars and 9 vans. There were 5 people in each car and 7 people in each van. How many people went on the hike?

asked Dec 31, 2015 by pady_1

1 answer

The instrument to draw a circle is a

asked Dec 31, 2015 by pady_1

0 answers

A rectangular restaurant kitchen is 10 metres long and 8 metres wide. What is its area?

asked Dec 31, 2015 by pady_1

0 answers

$16 \div \large\frac{2}{5}$

asked Dec 31, 2015 by pady_1

0 answers

Derek secured 18 marks out of 25 in a test. Express his marks as a percentage.

asked Dec 31, 2015 by pady_1

0 answers

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