Download App

PART - 2 CH - 10 Thermal Properties of Matter — Physics STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 SciencePhysicsPART - 2 CH - 10 Thermal Properties of Matter2 Marks
Question
Explain why :
an optical pyrometer (for measuring high temperature) calibrated for an ideal black-body radiation gives too low a value for the temperature of a red hot iron piece in the open, but gives a correct
value for the temperature when the same piece is in the furnace.
✓

Answer

Keeping the red hot iron piece in the open the emitted radiation energy $E=\sigma\left(T^4-T_0^4\right)$.
Where $T _{ o }$ is the temperature of the environment. So the measured temperature will be less but when this piece is in the furnace it will be $E =\sigma T ^4$. So the measured temperature will give correct value.

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 "2 Marks Questions" from PART - 2 CH - 10 Thermal Properties of Matter→PART - 2 CH - 10 Thermal Properties of Matter — all question types→Physics STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

A point charge Q is placed at the origin. Find the electrostatic energy stored outside the sphere of radius R centred at the origin.
→
Give one argument in favour of the fact that frictional force is a non conservative force.
→
The potential difference between the terminals of a 6.0V battery is 7.2V when it is being charged by a current of 2.0A. What is the internal resistance of the battery?
→
A block of mass 0.2kg is suspended from the ceiling by a light string. A second block of mass 0.3kg is suspended from the first block through another string. Find the tensions in the two strings. Take g = 10m/s2.
→
A water pump lifts water from a level 10m below the ground. Water is pumped at a rate of 30kg/ minute with negligible velocity. Calculate the minimum horsepower the engine should have to do this.
→
Two springs of force constants K and 2K are connected to a block of m as shown below. What is the frequency of oscillation of this block?

→
Give the magnitude and direction of the net force acting on a stone of mass 0.1kg, (Neglect air resistance throughout.)
Just after it is dropped from the window of a stationary train.
→
How is the speed of sound waves in atmosphere affected by the humidity and temperature?
→
The surface of water in a water tank on the top of a house is 4m above the tap level Find the pressure of water at the tap when the tap is closed Is it necessary to specify that the tap is closed? Take g = 10m/s2.
→
Why does a girl have to lean towards right when carrying a bag in her left hand?
→