MCQ
The sun emits a light with maximum wavelength $510\, mm$ while another star $X$ emits a light with maximum wavelength of $350\, nm$. What is the ratio of surface temperature of sun and the star $X$
  • A
    $2.1$
  • $0.68$
  • C
    $0.46$
  • D
    $1.45$

Answer

Correct option: B.
$0.68$
b
(b)As $\lambda \propto \frac{1}{T};$ so $\frac{{{T_1}}}{{{T_2}}} = \frac{{{\lambda _2}}}{{{\lambda _1}}} = \frac{{350}}{{510}} = 0.68$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Who discovered spin quantum number
A transistor is a/an
A capacitor of $10 \mu \mathrm{F}$ capacitance whose plates are separated by $10 \mathrm{~mm}$ through air and each plate has area $4 \mathrm{~cm}^2$ is now filled equally with two dielectric media of $\mathrm{K}_1=2, \mathrm{~K}_2=3$ respectively as shown in figure. If new force between the plates is $8 \mathrm{~N}$. The supply voltage is . . . .. . .V.
A common emitter amplifier is designed with $NPN$  transistor ($\alpha = 0.99$). The input impedance is $1 K \Omega$ and load is $10 K \Omega$The voltage gain will be
Find the acceleration of particle at $x = 5\,m$ with the help of graph. where $v-$ velocity and $x-$ displacement
The current density is a solid cylindrical wire of radius $R ,$ as a function of radial distance $r$ is given by $J ( r )= J _{0}\left(1-\frac{ r }{ R }\right) .$ The total current in the radial region $r =0$ to $r =\frac{ R }{4}$ will be
During blood transfusion the needle is inserted in a vein where the gauge pressure is $2000 \;Pa$. At what height (in $m$) must the blood container be placed so that blood may just enter the vein ?

Density of whole blood, $\rho=1.06 \times 10^{3} \;kg m ^{-3}$

With rise in temperature, the Young's modulus of elasticity
When we see an object, the image formed on the retina is
A square frame of side I carries a current $i$. The magnetic field at its centre is $B$. The same current is passed through a circular coil having the same perimeter as the square. The field at the centre of the circular coil is $B^{\prime}$. The ratio of $\frac{B}{B^{\prime}}$ is