Physics questions
20027 published questions with worked solutions.
- An object is at temperature of 400°C. At what temperature it would radiate energy twice as fast as initial rate? The temperature...
- Two bodies A & B have thermal emissivity's of the 0.16 & 0.81 resp. The outer surface areas of two bodies are same. The two...
- The energy radiated in one minute by a perfectly black body of surface area 300 cm^2, when its temperature is 227°C is (Stefan's...
- Two spheres P and Q of the Same colour having radii 8 cm and 2 cm respectively are maintained at temperatures 127°C and 527°C...
- A perfectly black body emits radiation at temperature T_1 K. If it is to radiate 16 times this power, its temperature T_2 will be
- The rate of loss of heat is same as :
- A black body is at a temperature of 500°k. It emits energy at a rate which is proportional to :
- The energy emitted by a black body at 727°C is E. How many times will be the energy emitted if the temperature if the body be...
- A metal ball of surface area 200 square cm, temperature 527°C is surrounded by a vessel at 27°C. If the emissivity of the metal...
- Two spheres P and Q of same colour having radii 8 cm and 2 cm are maintained at temperature 127°C and 527°C respectively. The...
- Two spares of the same material have radii 1 m & 4 m and temperature 4000 K and 2000 K respectively. The ratio of the energy...
- A black body radiates energy at the rate of E W/m^2 at a high temperature T K. When the temperature is reduced to T/2 K, the...
- A metal ball of surface area 200 cm^2 and temperature 527°C is surrounded by a vessel at 27°C. If the emissivity of the metal is...
- The temperature–time graphs obtained in Newton's cooling experiment is
- A sphere, a cube, a cone and a thin disc all made up of the same material and all have the same mass. If they are heated to the...
- A Solid cube and a sphere are made of the same material and both have the same surface area. If both are at the temperature of...
- Newton's law of cooling is used in laboratory for the determination of the specific heat of
- Newton's law of cooling holds good, if the temperature difference between body and surrounding is
- Newton's law of cooling is valid for
- Newton's law of cooling is also applicable to