Recent questions tagged 19

Which of the following is an amphoteric hydroxide?

asked Jul 8, 2019 by pady_1

1 answer

A steel bridge in a town is 200 m long. Where minimum temperature in winter is $10^{\circ}C$ and maximum in summer is $40^{\circ}C$. The change in length of the bridge from winter to summer is [ for steel alpha is $11 \times 10^{-6}/^{\circ}C$] :

asked Dec 19, 2018 by pady_1

0 answers

The maximum velocity of a particle executing SHM is $v$. If the amplitude is doubled and the time period of oscillation decreased to $\frac{1}{3}$ of its original value, the max velocity becomes :

asked Dec 19, 2018 by pady_1

0 answers

To generate power of $3.2\; MW$, the number of fissions $U^{235}$ per minute is : (Energy released per fission = $200\; MeV, \; 1eV =1.6 \times 10^{-19} J $)

asked Dec 19, 2018 by pady_1

0 answers

When an air bubble of radius $'r'$ rises from the bottom to the surface of a lake. Its radius becomes $\frac{5r}{4}$ (the pressure of the atmosphere is equal to the 10 m height to water column). If the temperature is contant and the surface tension is neglected the depth of the lake is :

asked Dec 11, 2018 by pady_1

0 answers

If in the circuit, power dissipation is 150 W, then $R$ is : <br>

asked Dec 11, 2018 by pady_1

0 answers

Two spherical bodies of mass M and 5M and radii R and 2R respecitvely are released in free space with initial separation between their centres equal to 12 R. If they attract each other due to gravitational force only, then the distance covered by the smaller body just before collision is :

asked Dec 11, 2018 by pady_1

0 answers

The EM wave from air enters a medium. The electric fields are $E_1 = E_{01} \hat{x} \cos [ 2 \pi v (\frac{z}{c} - t)]$ in air and $E_2 = E_{02} \hat{x} \cos [k(2z - ct)]$ in medium, where the wave number $k$ and frequency $v$ refer to their values in air. The medium is non-magnetic. If $\in_{r_1}$ and $\in_{r_2}$ refer to relative permittivities of air and medium respectively, which of the following options is correct ?

asked Dec 11, 2018 by pady_1

0 answers

The function $f : R \to \begin{bmatrix}-\frac{1}{2}, \frac{1}{2} \end{bmatrix}$ defined as $f(x) = \frac{x}{1+x^2}$, is :

asked Dec 11, 2018 by pady_1

1 answer

An observer looks at a distant tree of height 10 m with a telescope of magnifying power of 20. To the observer the tree appears :

asked Dec 11, 2018 by pady_1

0 answers

A proton (mass m) accelerated by a potential difference V flies through a uniform transverse magnetic field B. The field occupies a region of space by width $'d'$. If $'\alpha'$ be the angle of deviation of proton from initial direction of motion (see figure), the value of sin a will be : <br>

asked Dec 11, 2018 by pady_1

0 answers

A thin convex lens made from crown glass $( \mu = \frac{3}{2})$ has focal length f. When it is measured in two different liquids having refractive indices $\frac{4}{3}$ and $\frac{5}{3}$, it has the focal lengths $f_1$ and $f_2$ respectively. The correct relation between the focal lengths is :

asked Dec 11, 2018 by pady_1

0 answers

A piston filled with 0.04 mol of an ideal gas expands reversibly from 50.0 mL to 375 mL at a constant temperature of $37.0^0C$. Ad it does so, it absorbs 208 J of heat. The values of q and w for the process will be : <br> $(R = 8.314 \; J/mol\; K) \; (\ell n 7.5 = 2.01)$

asked Dec 11, 2018 by pady_1

0 answers

If $f : R \to R$ is a function defined by $f(x) = [x] \cos (\frac{2x-1}{2}) \pi$, where $[x]$ denotes the greatest integer function, then $f$ is

asked Dec 11, 2018 by pady_1

0 answers

A pulley of radius 2 m is rotated about its axis by a force $F=(20t-5t^2)$ Newton (where t is measured in seconds) applied tangentially. If the moment of inertia of the pulley about its axis of rotation made by the pulley before its direction of motion if reversed, is :

asked Dec 11, 2018 by pady_1

0 answers

The edge length of a face centered cubic cell of an ionic substance is 508 pm. If the radius of the cation is 110 pm, the radius of the anion is

asked Dec 11, 2018 by pady_1

0 answers

Consider a rubber ball freely falling from a height h = 4.9 m onto a horizontal elastic plate. Assume that the duration of collision is negligible and the collision with the plate is totally elastic. Then the velocity as a function of time the height as function of time will be

asked Nov 29, 2018 by pady_1

1 answer

Statement -1: $\sum^{n}_{r=0}(r+1)^nC_r=(n+2)2^{n-1}$ <br> Statement -2: $\sum^{n}_{r=0}(r+1)^nC_rX^r=(1+X)^n+nX(1+X)^{n-1}$

asked Nov 29, 2018 by pady_1

0 answers

For the Hyperbola $\frac{x^2}{\cos^2 \alpha} - \frac{y^2}{\sin^2 \alpha} = 1$, which of the following remains constant when $\alpha$ varies?

asked Nov 29, 2018 by pady_1

0 answers

In a common-base mode of a transistor, the collector current is 5.488 mA for an emitter current of 5.60 mA. The value of the base current amplification factor ($\beta$) will be:

asked Nov 13, 2018 by pady_1

0 answers

If $w = \frac{z}{z - \frac{1}{3} i } $ and $|w| = 1$, then $z$ lies on :

asked Nov 5, 2018 by pady_1

0 answers

If $S$ is stress and $Y$ is Young's modulus of material of a wire, the energy stored in the wire per unit volume is :

asked Nov 5, 2018 by pady_1

0 answers

The sum of the first n terms of the series $1^2 + 2.2^2 + 3^2 + 2.4^2 + 5^2 + 2.6^2+...$ is $\frac{n(n+1)^2}{2}$ when $n$ is even. When $n$ is odd the sum is

asked Nov 5, 2018 by pady_1

0 answers

Unpolarised light is incident from air on a plane surface of a material of refractive index $\mu$. At a particular angle of incidence 'i', it is found that the reflected and refracted rays are perpendicular to each other. Which of the following options is correct for this situation?

asked Aug 21, 2018 by pady_1

1 answer

Extraction of gold and silver involves leaching with $CN^–$ ion. Silver is later recovered by :

asked Aug 21, 2018 by pady_1

1 answer

Consider the molecules $CH_4, NH_3$ and $H_2O$. Which of the given statements is false?

asked Aug 21, 2018 by pady_1

1 answer

The name of complex ion, $[Fe(CN)_6]^{3–}$ is :

asked Aug 21, 2018 by pady_1

1 answer

The mean free path of molecules of a gas (radius 'r') is inversely proportional to :

asked Aug 20, 2018 by pady_1

1 answer

The amount of heat energy required to raise the temperature of 1 g of Helium at NTP, from $T_1 \; K$ to $T_2 \; K$ is :

asked Aug 20, 2018 by pady_1

1 answer

Liquid oxygen at 50 K is heated to 300 K at constant pressure of 1 atm. The rate of heating is constant. Which one of the following graphs represents the variation of temperature with time ?

asked Aug 20, 2018 by pady_1

1 answer

A current of 2 A flows through a $2 \Omega$ resistor when connected across a battery. The same battery supplies a current of 0.5 A when connect across a $ 9 \Omega$ resistor. The internal resistance of the battery is :

asked Aug 16, 2018 by pady_1

1 answer

A conducting circular loop is placed in a uniform magnetic field, B = .025 T with its e plane perpendicular to the loop The radius of the loop is made to shrink at a constant rate of 1 $mms^{–1}$. The induced e.m.f. when the radius is 2 cm, is –

asked Jul 26, 2018 by pady_1

1 answer

The driver of a car traveling with speed 30 m/sec towards a hill sounds a horn of frequency 600 Hz. If the velocity of sound in air is 330 m/s, the frequency of reflected sound as heard by driver is :

asked Jul 26, 2018 by pady_1

1 answer

If Q, E and W denote respectively the heat added, change in internal energy and the work done by a closed cycle process, then :

asked Jul 26, 2018 by pady_1

1 answer

The particle executing simple harmonic motion has a ienetic energy $K_0 \cos^2 ωt$. The maximum values of the potential energy and the total energy are respectively:-

asked Jul 26, 2018 by pady_1

1 answer

300 J of work is done in sliding a 2 kg block up an inclined plane of height 10m. Taking $g = 10 m/s^2$, work done against friction is

asked Jul 25, 2018 by pady_1

1 answer

The nuclei of which one of the following pairs of nuclei are isotones :

asked Jul 24, 2018 by pady_1

1 answer

According to Einstein's photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of incident radiation is :-

asked Jul 24, 2018 by pady_1

1 answer

A equiconvex lens is cut into two halves along (i) XOX' and (ii) YOY' as shown in the figure. Let f, f' f" be the focal lengths of the complete lens, of each half in case (i), and of each half in case (ii), respectively Choose the correct statement from the following-

asked Jul 24, 2018 by pady_1

1 answer

Consider two rods of same length and different specific heats ($S_1$, $S_2$), conductivities ($K_1$, $K_2$) a area of cross-sections ($A_1$, $A_2$) and both having temperature $T_1$ and $T_2$ at their ends. If rate of lo of heat due to conduction is equal, then :-

asked Jul 23, 2018 by pady_1

1 answer

The total energy of particle performing SHM depend on :-

asked Jul 20, 2018 by pady_1

1 answer

Electric field atcentre O of semicircle of radius 'a' having linear charge density $\lambda$ given is given by O a

asked Jul 20, 2018 by pady_1

1 answer

Light enters at an angle of incidence in a transparent rod of refractive index n. For what value of the refractive index of the material of the rod, the light once entered into it will not leave it through its lateral face whatsoever be the value of angle of incidence :

asked Jun 15, 2018 by pady_1

0 answers

Pick the odd one out : SUGARCANE, COFFEE, TOBACCO, RICE

asked Dec 31, 2015 by pady_1

0 answers

Kayla swam 6 laps on Sunday, 15 laps on Monday, 24 laps on Tuesday, 33 laps on Wednesday, and 42 laps on Thursday. If this pattern continues, how many laps will Kayla swim on Friday?

asked Dec 31, 2015 by pady_1

0 answers

Each bag of bananas weighs 5 kgs 290 grams. If the total weight of a sack containing bananas bags is 84.64 kgs, then how many bags are in the sack?

asked Dec 31, 2015 by pady_1

0 answers

What is the multiplicative inverse of 1

asked Dec 31, 2015 by pady_1

0 answers

If 13 Kgs. of barley is required to make food for 390 people, then how many kilograms will be needed to make food for 2190 people?

asked Dec 31, 2015 by pady_1

0 answers

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