The graph. Shown in the adjacent diagram, represents the variatio… - Vidyadip

MCQ

The graph. Shown in the adjacent diagram, represents the variation of temperature $(T)$ of two bodies, $x$ and $y$ having same surface area, with time $(t)$ due to the emission of radiation. Find the correct relation between the emissivity

A
${e_x} > {e_y}$ and ${a_x} < {a_y}$
B
${e_x} > {e_y}$ and ${a_x} < {a_y}$
✓
${e_x} < {e_y}$ and ${a_x} > {a_y}$
D
${e_x} > {e_y}$ and ${a_x} > {a_y}$

✓

Answer

Correct option: C.

${e_x} < {e_y}$ and ${a_x} > {a_y}$

c
(c) Rate of cooling $\left( { - \frac{{dT}}{{dt}}} \right)\; \propto $ emissivity $(e)$
From graph, ${\left( { - \frac{{dT}}{{dt}}} \right)_x} > {\left( { - \frac{{dT}}{{dt}}} \right)_y}$

==> ${e_x} > {e_y}$
Further emissivity $(e)$ $\propto$ Absorptive power $(a)$

==> ${a_x} > {a_y}$
( good absorbers are good emitters).

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

Explore more

More "M.C.Q (1 Marks)" from 10.2 , transmission of heat→10.2 , transmission of heat — all question types→Physics STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

In Melde’s experiment in the transverse mode, the frequency of the tuning fork and the frequency of the waves in the strings are in the ratio

A constant current of 2.8A exists in a resistor. The rms current is:

At $0 \;K$ which of the following properties of a gas will be zero

The uncertain digit in the measurement of a length reported as $41.68 \,cm$ is ...........

A uniform sphere of weight $W$ and radius $3\,m$ is being held by a string of length $2\,m$ , attached to a frictionless wall as shown in the figure. The tension in the string will be

An iron sphere of mass 10kg has the same diameter as an aluminium sphere of mass is $3.5\ kg.$ Both spheres are dropped simultaneously from a tower. When they are $10\ m$ above the ground, the have the same:

Action and reaction:

Act on two different objects.
Have equal magnitude.
Have opposite directions.
Have resultant zero.

The centre of mass of system of particles does not depend on

Physical independence of force is a consequence of:

Three stars $A, B, C$ have surface temperatures $T _{A} ,T _{B}, T _{C}$ respectively. Star $A$ appears bluish, star $B$ appears reddish and star $C$ yellowish. Hence,