A black rectangular surface of area A emits energy E per second at `27^circC`. If length and breadth are reduced to one third of initial value and temperature is raised to `327^circC`, then energy emitted per second becomesA. `(4E)/(9)`B. `(7E)/(9)`C. `(10E)/(9)`D. `(16E)/(9)`

A black rectangular surface of area A emits energy E per second at `27

1.	A black rectangular surface of area A emits energy E per second at `27^circC`. If length and breadth are reduced to one third of initial value and temperature is raised to `327^circC`, then energy emitted per second becomesA. `(4E)/(9)`B. `(7E)/(9)`C. `(10E)/(9)`D. `(16E)/(9)`
Answer» Correct Answer - D `T_(1)=27+273=300K,L_(2)=(1)/(3)L_(1)` `T_(2)=273+32=600K` `(E_(2))/(E_(1))=(A_(2))/(A_(1))((T_(2))/(T_(1)))^(4)` `=(L_(2)b_(2))/(L_(1)b_(1))xx((600)/(300))^(4)` `=(1)/(3)xx(1)/(3)=16` `E_(2)=(16)/(9)E_(1)`.

Discussion

No Comment Found

Related InterviewSolutions

A liquid drop having surface energy E is spread into 512 droplets of same size. The final surface energy of the droplets isA. 2 EB. 4EC. 8ED. 12 E
Two wires having same length and material are stretched by same force. Their diameters are in the ratio 1:3. The ratio of strain energy per unit volume for these two wires (smaller to larger diameter) when stretched isA. `3:1`B. `9:1`C. `27:1`D. `81:1`
If the end correction of an open pipe is 0.8 cm, then the inner radius of that pipe will beA. `(1)/(3)cm`B. `(2)/(3)cm,`C. `(3)/(2)cm`D. 0.2cm
When open pipe is closed from one end, then third overtone of closed pipe is higher in frequency by 150 Hz than second overtone of open pipe. The fundamental frequency of open end pipe will beA. 75 HzB. 150 HzC. 225 HzD. 300 Hz
A black rectangular surface of area A emits energy E per second at `27^circC`. If length and breadth are reduced to one third of initial value and temperature is raised to `327^circC`, then energy emitted per second becomesA. `(4E)/(9)`B. `(7E)/(9)`C. `(10E)/(9)`D. `(16E)/(9)`
Assuming the expression for the pressure exerted by the gas on the walls of the container, it can be shown that pressure isA. `[(1)/(3)]^(rd)` kinetic energy per unit volume of a gasB. `[(2)/(3)]^(rd)` kinetic energy per unit volume of a gasC. `[(3)/(4)]^(th)` kinetic energy per unit volume of a gasD. `(3)/(2)xx` kinetic energy per unit volume of a gas
In vertical circular motion, the ratio of kinetic energy of a particle at highest point to that at lowest point isA. 5B. 2C. `0.5`D. `0.2`
Two bodies of masses m and 4m are placed at a distance r. The gravitational potential at a point on the line joining them where the gravitational field is zero is:A. `-(4Gm)/(r)`B. `-(8Gm)/(r)`C. `-(16Gm)/(r)`D. `-(32Gm)/(r)`
Calculate the angular speed of the hour hand of a clock .A. `(1)/(50)`B. `(1)/(60)`C. `(1)/(120)`D. `(1)/(720)`
When the observer moves towards the stationary source with velocity, `v_1`, the apparent frequency of emitted note is `f_1`. When the observer moves away from the source with velocity `v_1`, the apparent frequency is `f_2`. If v is the velocity of sound in air and `f_1/f_2` = 2,then `v/v_1` = ?A. 2B. 3C. 4D. 5

A black rectangular surface of area A emits energy E per second at `27^circC`. If length and breadth are reduced to one third of initial value and temperature is raised to `327^circC`, then energy emitted per second becomesA. `(4E)/(9)`B. `(7E)/(9)`C. `(10E)/(9)`D. `(16E)/(9)`

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment