Q. Solar radiation emitted by sun resembles that emitted by a black body at a temperature of $6000\text{ K}$ . Maximum intensity is emitted at a wavelength of about $4800 \mathring{A} $ . If the sun were to cool down from $6000\text{ K}$ to $3000\text{ K}$ , then the peak intensity would occur at a wavelength

NTA AbhyasNTA Abhyas 2020Thermal Properties of Matter Report Error

A

$6000\mathring{A} $

0%

B

$9600\mathring{A} $

100%

C

$2400\mathring{A} $

0%

D

$19200\mathring{A} $

0%

Solution:

We know that
$\frac{\lambda _{m_{2}}}{\lambda _{m_{1}}}=\frac{T_{1}}{T_{2}}$
$\Rightarrow \lambda _{m_{2}}=9600 \, \mathring{A} $

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$6000\mathring{A} $

$9600\mathring{A} $

$2400\mathring{A} $

$19200\mathring{A} $

We know that $\frac{\lambda _{m_{2}}}{\lambda _{m_{1}}}=\frac{T_{1}}{T_{2}}$ $\Rightarrow \lambda _{m_{2}}=9600 \, \mathring{A} $

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1. A bob of mass $\text{M}$ is suspended by a massless string of length $\text{L}$ . The horizontal velocity $\text{v}$ at position $\text{A}$ is just sufficient to make it reach point $\text{B}$ . The angle $\theta $ at which the speed of the bob is half of that at $\text{A}$ satisfies

2. The velocity displacement graph of a particle moving along a straight line is - The most suitable acceleration-displacement graph will be

3. A drum of radius $R$ and mass $M$ rolls down without slipping along an inclined plane of angle $\theta $ . The frictional force

4. A sample of $^{18} F$ is used internally as a medical diagnostic tool to look for the effects of the positron decay $\left(\right. T_{\frac{1}{2}} = 110 \, \text{min} \left.\right)$ . How long does it take for $\text{99\%}$ of the $^{18}F$ to decay?

5. If the mass of neutron $=1.7\times 10^{- 27}\text{ kg}$ , then the de-Broglie wavelength of neutron of energy $\text{3 eV}$ is $\left(\right.h=6.6\times \left(10\right)^{- 34 \, }J-s\left.\right)$

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1. If the temperature difference on the two sides of a wall increases from $ 100{}^\circ C $ to $ 200{}^\circ C $ , its thermal conductivity

2. A wall is made of equally thick layers $A$ and $B$ of different materials. Thermal conductivity of $A$ is twice that of $B$. In the steady state, the temperature difference across the wall is $36^{\circ}C$. The temperature difference across the layer $A$ is

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4. A black body at $1373$ $℃$ emits maximum energy corresponding to a wavelength of $1.78$ microns. The temperature of the moon for which $\lambda _{m}=14$ micron would be

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1. If $E$ and $G$ respectively denote energy and gravitational constant, then $\frac{ E }{ G }$ has the dimensions of:

2. The de Broglie wavelength of an electron moving with kinetic energy of $144 \,eV$ is nearly

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4. A wheel with $20$ metallic spokes each $1\, m$ long is rotated with a speed of $120\, rpm$ in a plane perpendicular to a magnetic field of $0.4\, G$. The induced emf between the axle and rim of the wheel will be, $(1 G = 10^{-4}\, T)$

5. A barometer is constructed using a liquid (density $= 760 \,kg/m^{3})$ What would be the height of the liquid column, when a mercury barometer reads $76\, cm$ ? (density of mercury $= 13600 kg/m^{3})$

Latest Updates

We know that
$\frac{\lambda _{m_{2}}}{\lambda _{m_{1}}}=\frac{T_{1}}{T_{2}}$
$\Rightarrow \lambda _{m_{2}}=9600 \, \mathring{A} $

2. The velocity displacement graph of a particle moving along a straight line is -

The most suitable acceleration-displacement graph will be

5. A barometer is constructed using a liquid (density $= 760 \,kg/m^{3})$ What would be the height of the liquid column, when a mercury barometer reads $76\, cm$ ?
(density of mercury $= 13600 kg/m^{3})$