Heat

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Heat Transfer and Newton’s Law of Cooling (1.3)

Students Manual In the present experiment, the students will heat a metallic rod in a temperature-regulated furnace or on a hot plate and place it inside a cavity approximating a blackbody cavity. The temperature on the surface of the heated object as well as inside the cavity will be monitored with time. The rate of cooling will be determined and the impact of forced convection currents will also be investigated. The students will learn how to interface temperature sensors with the computer. In the course of the measurements, the students will also verify Newton’s law of cooling as a special case.
Matlab Codes Heat
Lab View Code Thermal
Sample Results

Forced and natural convection plot
Log plot

Further Readings and References

"Heating Water: Rate Correction Due to Newtonian Cooling", James O' Connell, The Physics Teacher 37, 551-552 (1999).
"Introducing Specific Heat Through Cooling Curves", C.R. Mattos and A. Gasper, The Physics Teacher 40, 415-416 (2002).

"Do Darker Objects Really Cool Faster", Richard A. Bartels, American Association of Physics Teacher 58 (3), 244-248 (1990).

Pictorial procedure (1.3)

1. Provided apparatus
1. Provided apparatus
2. Cavity with cooling fan cable
2. Cavity with cooling fan cable
3. Measuring the mass of a cylinder
3. Measuring the mass of a cylinder
4. Measuring the diameter of a cylinder
4. Measuring the diameter of a cylinder
5. Cylinder inside the steel box
5. Cylinder inside the steel box
6. Attaching thermocouple to the cylinder
6. Attaching thermocouple to the cylinder
7. Placing a lid on the steel box to avoid heat loss
7. Placing a lid on the steel box to avoid heat loss
8. Always use gloves and tong to remove the heated cylinder from steel box
8. Always use gloves and tong to remove the heated cylinder from steel box
9. Placing a heated cylinder inside the cavity
9. Placing a heated cylinder inside the cavity
10. Attaching E2 thermocouple to the clamp
10. Attaching E2 thermocouple to the clamp
11. Attaching a labeled E1 thermocouple inside the cavity and E2 with the cylinder
11. Attaching a labeled E1 thermocouple inside the cavity and E2 with the cylinder
12. Preparing Labview file for forced convection
12. Preparing Labview file for forced convection
13. Experimenatl setup for demonstarating forced concvection alongwith thermocouple calibration
13. Experimenatl setup for demonstarating forced concvection alongwith thermocouple calibration
14. Closing the base of the cavity
14. Closing the base of the cavity
15. Labview file for radiative and convective losses
15. Labview file for radiative and convective losses
16. Setup for simultaneous radiative and convective losses
16. Setup for simultaneous radiative and convective losses
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