MTG NEET Physics
Temperature of body T is slightly more than the temperature of the surrounding T0. Its rate of cooling (R) versus temperature of body (T) is plotted, its shape would be
12
Sep
Temperature of body T is slightly more than the temperature of the surrounding T0. Its rate of cooling (R) versus temperature of body (T) is plotted, its shape would be its shape would be Temperature of body T is slightly more than the temperature of the surrounding T0. Its rate of cooling (R) versus temperature [...]
A cup of tea cools from 80∘C to 60∘C in one minute. The ambient temperature is 30∘C . In cooling from 60∘C to 50∘C . It will take:
12
Sep
A cup of tea cools from 80∘C to 60∘C in one minute. The ambient temperature is 30∘C . In cooling from 60∘C to 50∘C . It will take: A cup of tea cools from 80∘C to 60∘C in one minute. The ambient temperature is 30∘C . In cooling from 60∘C to 50∘C . It will [...]
In a 10-metre-deep lake, the bottom is at a constant temperature of 4°C. The air temperature is constant at -4°C. The thermal conductivity of ice is 3 times that of water. Neglecting the expansion of water on freezing, the maximum thickness of ice will be
12
Sep
In a 10-metre-deep lake, the bottom is at a constant temperature of 4°C. The air temperature is constant at -4°C. The thermal conductivity of ice is 3 times that of water. Neglecting the expansion of water on freezing, the maximum thickness of ice will be In a 10-metre-deep lake the bottom is at a constant [...]
Three separate segments of equal area A1 ,A2 and A 3 are shown in the energy distribution curve of a blackbody radiation . if n1 , n2 and n3 are numbers of photons emitted per unit time corresponding to each area segment respectively then.
12
Sep
Three separate segments of equal area A1 ,A2 and A 3 are shown in the energy distribution curve of a blackbody radiation . if n1 , n2 and n3 are numbers of photons emitted per unit time corresponding to each area segment respectively then. A2 and A 3 are shown in [...]
Two bodies A and B have emissivities 0.3 and 0.6 respectively have maximum spectral emissive powers at wavelength 4000 Å and 2000 Å respectively. The ratio of their emissive powers at A and B at these temperatures is:
12
Sep
Two bodies A and B have emissivities 0.3 and 0.6 respectively have maximum spectral emissive powers at wavelength 4000 Å and 2000 Å respectively. The ratio of their emissive powers at A and B at these temperatures is: A difference of temperature of 25^∘C is equivalent to a difference of. September 12, 2021 Category: Chapter [...]
Spheres P and Q are uniformly constructed from the same material which is a good conductor of heat and the radius of Q is thrice the radius of P. The rate of fall of temperature of P is x times that of Q. When both are at the same surface temperature, the value of x is :
12
Sep
Spheres P and Q are uniformly constructed from the same material which is a good conductor of heat and the radius of Q is thrice the radius of P. The rate of fall of temperature of P is x times that of Q. When both are at the same surface temperature, the value of x [...]
The wall with a cavity consists of two layers of brick separated by a layer of air. All three layers have the same thickness and the thermal conductivity of the brick is much greater than that of air. The left layer is at a higher temperature than the right layer and steady state condition exists. Which of the following graphs predicts correctly the variation of temperature T with distance d inside the cavity?
12
Sep
The wall with a cavity consists of two layers of brick separated by a layer of air. All three layers have the same thickness and the thermal conductivity of the brick is much greater than that of air. The left layer is at a higher temperature than the right layer and steady state condition exists. [...]
Two bodies P and Q have thermal emissivities of ϵ_(P) and ϵ Q respectively. Surface areas of these bodies are same and the total radiant power is also emitted at the same rate. If temperature of P is T_P kelvin then temperature of Q i.e. T_Q is
11
Sep
Two bodies P and Q have thermal emissivities of ϵ_(P) and ϵ Q respectively. Surface areas of these bodies are same and the total radiant power is also emitted at the same rate. If temperature of P is T_P kelvin then temperature of Q i.e. T_Q is A difference of temperature of 25^∘C is equivalent [...]
The intensity of radiation emitted by the sun has its maximum value at a wavelength of 510 nm and that emitted by the North Star has the maximum value at 350 nm. If these stars behave like black bodies, then the ratio of the surface temperature of the sun and North star is:
11
Sep
The intensity of radiation emitted by the sun has its maximum value at a wavelength of 510 nm and that emitted by the North Star has the maximum value at 350 nm. If these stars behave like black bodies, then the ratio of the surface temperature of the sun and North star is: A difference [...]
The spectral emissive power Eλ for a body at temperature T1 is plotted against the wavelength and area under the curve is found to be A. At a different temperature T2 the area found to be 9A. Then λ2 /λ1 is :
11
Sep
The spectral emissive power Eλ for a body at temperature T1 is plotted against the wavelength and area under the curve is found to be A. At a different temperature T2 the area found to be 9A. Then λ2 /λ1 is : A difference of temperature of 25^∘C is equivalent to a difference of. September [...]