Recent questions tagged class12

Integrate : $\int x^5 \sec^2 (7x^6+9) dx$

asked Dec 23, 2013 by meena.p

1 answer

The threshold frequency for a certain metal is $3.3 \times 1014Hz$. If light of frequency $8.2 \times 1014 Hz$ is incident on the metal, predict the cutoff voltage for the photoelectric emission.

asked Dec 23, 2013 by thanvigandhi_1

1 answer

Integrate : $\int \large\frac{\sqrt {\cos^{-1}(4x)}}{\sqrt {1-16x^2}}$$dx$

asked Dec 23, 2013 by meena.p

1 answer

A 100 W sodium lamp radiates energy uniformly in all directions. The lamp is located at the centre of a large sphere that absorbs all the sodium light which is incident on him. The $ \lambda$ of sodium light is 589 nm. At what rate are the photons delivered to the sphere ?

asked Dec 23, 2013 by thanvigandhi_1

1 answer

Integrate : $ \int x^2. e^{\Large x^3}. \cos (e^{\Large x^3}).dx$

asked Dec 23, 2013 by meena.p

1 answer

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

asked Dec 23, 2013 by meena.p

1 answer

The energy flux of sunlight reaching the surface of the earth is $ 1.388 \times 10^3 \: W/m^2$. How many photons per square meter are incident on earth per second ? Assume that the photons in the sunlight have an average wavelength of 550 nm.

asked Dec 23, 2013 by thanvigandhi_1

1 answer

Integrate: $ \int \large\frac{x^3 \tan ^{-1} x^4 }{1+x^8}$$dx$

asked Dec 23, 2013 by meena.p

1 answer

Integrate : $ \int \sec^4 x dx$

asked Dec 23, 2013 by meena.p

1 answer

Monochromatic light of wavelength 632.8 nm is produced by a helium-neon laser. The power emitted is 9.42 mW. How many photons per second, on the average, arrive at a target irradiated by this beam ? (Assume the beam to have uniform cross - section which is less than the target area )

asked Dec 23, 2013 by thanvigandhi_1

1 answer

Integrate: $ \int \large\frac{dx}{x \sqrt {1-x^3}}$$= a \log \bigg| \large\frac{\sqrt {1-x^3}-1}{\sqrt {1-x^3}+1}\bigg|$ find the value of a

asked Dec 23, 2013 by meena.p

1 answer

The photoelectric cut-off voltage in a certain experiment is 1.5 V. What is the maximum kinetic energy of photoelectrons emitted ?

asked Dec 23, 2013 by thanvigandhi_1

1 answer

If $y(x) = \Large \int \limits_{\frac{\pi^2}{16}}^{\normalsize x^2} \large\frac{\cos x . \cos \sqrt \theta d\theta}{1+\sin^2 \sqrt \theta}$, find $\;y'(\pi)$

asked Dec 23, 2013 by meena.p

1 answer

If function $f(x)$ is differentiable at $x=a$ then $\lim\limits_{x\to a}\large\frac{x^2f(a)-a^2f(x)}{x-a}$ is

asked Dec 23, 2013 by sreemathi.v

1 answer

Integrate : $ \int \sqrt {\tan x }+ \sqrt {\cot x }dx$

asked Dec 23, 2013 by meena.p

1 answer

Evaluate $ \Large \int $$ \large \frac{\log x }{(1+\log x)^2}$$dx$

asked Dec 23, 2013 by meena.p

1 answer

Let $f : R\rightarrow R$ be a positive increasing function with $\lim\limits_{x\to 0}\large\frac{f(3x)}{f(x)}$$=1$. Then $\lim\limits_{x\to \infty}\large\frac{f(2x)}{f(x)}$ = ?

asked Dec 23, 2013 by sreemathi.v

1 answer

Let $f$ be differentiable for all $x$. If $f(1)=-2$ and $f'(x)\geq 2$ for $x\in [1,6]$ then

asked Dec 23, 2013 by sreemathi.v

1 answer

The work function of caesium metal is $2.14 \;eV$. When light of frequency $ 6 \times 10^{14}Hz$ is incident on the metal surface , photoemmision of electron occurs. What is the stopping potential of the emitted photoelectrons ?

asked Dec 23, 2013 by thanvigandhi_1

1 answer

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

asked Dec 23, 2013 by meena.p

1 answer

The value of $\lim\limits_{x\to 0}\large\frac{\int\limits_0^{x^2} \sec^2tdt}{x\sin x}$ is

asked Dec 23, 2013 by sreemathi.v

1 answer

The maximum frequency of X-rays produced by 30 kv electrons is

asked Dec 23, 2013 by thanvigandhi_1

1 answer

Integrate : $\int \sqrt {(\sec x -1)}.dx$

asked Dec 23, 2013 by meena.p

1 answer