Why do hot objects tend to emit shorter wavelength? So how do the temperature and wavelength related and why do hot objects tend to emit shorter wavelength? 
 A: How are the temperature and the wavelength spectrum of the light emitted by a hot body related? This connection is described by Planck's law:
$$ B_\lambda(\lambda, T) =\frac{2hc^2}{\lambda^5}\frac{1}{ e^{\frac{hc}{\lambda k_\mathrm B T}} - 1}$$
Where $B_\lambda$ is the spectral radiance per unit wavelength, $\lambda$ is the wavelength emitted, T is the temperature, $h$ is the Planck constant, $c$ is the speed of light, and $k_B$ is the Boltzmann constant. 
When you plug in increasing temperatures into the formula and see how the spectrum for each ends up looking, you will observe two things. First, that $B_\lambda$ increases for each $\lambda$. Second, that $B_\lambda$ increases more at shorter wavelengths. So there's a shift towards shorter wavelengths at increasing temperatures.
Why? For an informal, qualitative answer, you need to consider two things. First, that a hotter body  has more thermal energy to emit in the form of radiation. Second, that electromagnetic radiation comes in little packages called photons. The energy of each of these photons is described in Planck's relation, not to be confused with Planck's law, which is $E = h \cdot f$, where f is the frequency of the light, or $c/\lambda$ . So a hotter body has two ways of emitting more energy: It can emit more photons, or it cn emit photons with more energy, i.e., photons of a shorter wavelength. In practice, it does some of both. 
A formal, quantitative, theoretically-rigorous explanation of the "why" is beyond the scope of what I can write on Stack Exchange. If you're interested in one,  I recommend that you start with the Wikipedia links above. To find out even more, you can go to your library and check out a books with titles like "thermodynamics" or "statistical physics" in them. 
A: According to Wien's law , $\Omega T = \rm constant$, hence the objects having higher surface temperature radiate energy with the shorter  wavelengths.
