Recent questions tagged class12

De Broglie used Einstein’s special theory of relatively together with Plank’s quantum theory to establish the wave property of particles. He gave fundamental relationship $ \large\frac{ \lambda h}{p}$; where $ lambda$ and $p$ are wavelength and momentum respectively and $h$ is Plank’s constant. A de-Broglie wave associated with an electron can form a standing wave between the atoms arranged in a one dimensional array with node at each of the atomic sites. A standing wave is formed when the distance between the atoms of any array is $d = 3A^{\circ}$. A similar standing wave is again formed if $d = 3.5 A^:{\circ}$ but not for any intermediate value of $d$. For thermal neutron at ordinary temperature, energy is given by relation $E = kT$, where $K$ is Boltzmann constant mass of Neutron is $1.67\times10^{–23} g$. The least value of d for which standing wave can be formed is

asked Dec 30, 2013 by thanvigandhi_1

1 answer

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 vs. $ \lambda$ curve is

asked Dec 30, 2013 by thanvigandhi_1

1 answer

Integrate : $\int \large\frac{1+\tan ^2 x }{1+\tan x }$$dx$

asked Dec 30, 2013 by meena.p

1 answer

The quark structure of protons and neutrons appears at the minute length-scale of $10^{-15}m$ or less. This structure was first probed in early 1970’s using high energy electron beams produced by a linear accelerator at Stanford, USA. Guess the order of energy of these electron beams. (Take wavelength of a proton = $10^{-15}m$ ; rest mass of energy of electron = $0.511\: MeV$)

asked Dec 30, 2013 by thanvigandhi_1

1 answer

Integrate : $\int \large\frac{5}{8}.x.e{^{\Large x^2}}. \sec (e^{\Large x^2}).\tan (e^{x^2})dx$

asked Dec 30, 2013 by meena.p

1 answer

Integrate : $\int \sqrt {1+\sin x }dx$

asked Dec 30, 2013 by meena.p

1 answer

Light of Intensity $10^{-5}W/m^2$ falls on a sodium photo-cell of surface area $2\: cm^2$ .Assuming that the top 5 layers of sodium absorb the incident energy, estimate time required for photoelectric emission in the wave – picture of radiation.( Effective atomic area of a sodium atom = $10^{-20}m^2$ )

asked Dec 30, 2013 by thanvigandhi_1

1 answer

Integrate : $\int \large\frac{\sin ^{-1} x }{(1-x^2)^{3/2}}$$dx$

asked Dec 30, 2013 by meena.p

1 answer

A monoenergetic electron beam with speed of $ 5.2 \times 10^6\: m/s$ is subjected to a magnetic field of $1.3 \times 10^{-4}T$ normal to the beam velocity. What is the radius of the circle traced by the beam, given $ \large\frac{e}{m}$ for electron equals $1.76 \times 10^{11}C /kg$?

asked Dec 30, 2013 by thanvigandhi_1

1 answer

Integrate : $\int \large\frac{\sin x +\cos x }{\sqrt {\sin 2x}}$$dx$

asked Dec 30, 2013 by meena.p

1 answer

Integrate : $\int \large\frac{\cos 2 x}{\sin ^2 x \cos ^2 x }$$dx$

asked Dec 30, 2013 by meena.p

1 answer

Integrate : $\int \large\frac{1- x \sin x +\cos x }{x(1- \cos x )}$$dx$

asked Dec 30, 2013 by meena.p

1 answer

Integrate : $\int \large\frac{\sec x cosec x}{\log (\tan x )}$$dx$

asked Dec 30, 2013 by meena.p

1 answer

Integrate : $\int \sqrt {\large\frac{1-x}{1+x}}.\frac{1}{x}$$dx$

asked Dec 30, 2013 by meena.p

1 answer

Integrate : $\int \sqrt {\tan \theta} . d \theta $

asked Dec 30, 2013 by meena.p

1 answer

Integrate $ \int \limits _0^1 \tan ^{-1}(x^2+1-x)dx$

asked Dec 30, 2013 by meena.p

1 answer

Integrate : $\int \limits_0^{\pi/2} \bigg( \large\frac{\theta}{ \sin \theta }\bigg)^2.$$ d \theta $

asked Dec 30, 2013 by meena.p

1 answer

Integrate : $\int \sqrt{\large\frac{x}{1+x}}$$dx$

asked Dec 30, 2013 by meena.p

1 answer

If $\log (x+y)=2xy$ then $y'(0)=$

asked Dec 30, 2013 by sreemathi.v

1 answer

The shortest distance between the lines $\large\frac{x-6}{1}=\frac{2-y}{2}=\frac{z-2}{2}$ and $\large\frac{x+4}{3}=\frac{y}{-2}=\frac{1-z}{2}$ is?

asked Dec 29, 2013 by rvidyagovindarajan_1

1 answer

The vector $\overrightarrow a=\alpha\hat i+2\hat j+\beta\hat k$ lies in the plane of the vectors $\overrightarrow b=\hat i+\hat j$ and $\overrightarrow c=\hat j+\hat k$ and bisects the angle between $\overrightarrow b\:\:and\:\:\overrightarrow c$, then $(\alpha,\beta)=?$

asked Dec 29, 2013 by rvidyagovindarajan_1

1 answer

If the equation of the plane containing the line $\large\frac{x-x_1}{l}=\frac{y-y_1}{m}=\frac{z-z_1}{n}$ is $a(x-x_1)+b(y-y_1)+c(z-z_1)=0$, then ?

asked Dec 29, 2013 by rvidyagovindarajan_1

1 answer

The direction ratio of the normal to the plane through $(1,0,0),(0,1,0)$, which makes $\large\frac{\pi}{4} $ with the plane $x+y=3$ is ?

asked Dec 28, 2013 by rvidyagovindarajan_1

1 answer

The equation of the plane passing through the point $(3,2,0) $ and the line $\large\frac{x-3}{1}=\frac{y-6}{5}=\frac{z-4}{4}$ is ?

asked Dec 28, 2013 by rvidyagovindarajan_1

1 answer

The two lines whose equations are given by $x=ay+b,\:\:z=cy+d\:\:\:and\:\:\:x=a'y+b',\:\:z=c'y+d'$ are $\perp$ if

asked Dec 28, 2013 by rvidyagovindarajan_1

1 answer