1
MHT CET 2023 10th May Morning Shift
+1
-0

A black body radiates maximum energy at wavelength '$$\lambda$$' and its emissive power is $$\mathrm{E}$$. Now due to change in temperature of that body, it radiates maximum energy at wavelength $$\frac{2 \lambda}{3}$$. At that temperature emissive power is

A
$$\frac{51 \mathrm{E}}{8}$$
B
$$\frac{81 \mathrm{E}}{16}$$
C
$$\frac{61 E}{27}$$
D
$$\frac{71 \mathrm{E}}{19}$$
2
MHT CET 2023 10th May Morning Shift
+1
-0

A Carnot engine with efficiency $$50 \%$$ takes heat from a source at $$600 \mathrm{~K}$$. To increase the efficiency to $$70 \%$$, keeping the temperature of the sink same, the new temperature of the source will be

A
$$360 \mathrm{~K}$$
B
$$1000 \mathrm{~K}$$
C
$$900 \mathrm{~K}$$
D
$$300 \mathrm{~K}$$
3
MHT CET 2023 10th May Morning Shift
+1
-0

A piece of metal at $$850 \mathrm{~K}$$ is dropped in to $$1 \mathrm{~kg}$$ water at $$300 \mathrm{~K}$$. If the equilibrium temperature of water is $$350 \mathrm{~K}$$ then the heat capacity of the metal, expressed in $$\mathrm{JK}^{-1}$$ is $$(1 \mathrm{~cal}=4.2 \mathrm{~J})$$

A
420
B
240
C
100
D
No Solution
4
MHT CET 2023 10th May Morning Shift
+1
-0

Heat energy is incident on the surface at the rate of X J/min . If '$$a$$' and '$$r$$' represent coefficient of absorption and reflection respectively then the heat energy transmitted by the surface in '$$t$$' minutes is

A
$$(a+r) x t$$
B
$$\frac{(\mathrm{a}+\mathrm{r})}{\mathrm{xt}}$$
C
$$-(a+r) x t$$
D
$$\frac{\mathrm{xt}}{(\mathrm{a}+\mathrm{r})}$$
EXAM MAP
Medical
NEET