Experiment #2 investigated the effect of changing the cross-sectional area of a thermal conductor on its temperature profile. Sensors were placed along a brass conductor to measure the temperature at various points as heat was applied. The temperature and heat input power were recorded at steady state intervals. Varying the input power affected the overall heat transfer coefficient, with higher input power resulting in a lower coefficient. The calculated and theoretical heat transfer coefficients differed due to differences in experimental variables.

1. Experiment # 2
Objective:
To investigate the effect of a change in the cross section area on the temperature profile along a
thermal conductor.
Apparatus:
Fig2.1 (Heat conduction unit)
Procedure:
 Make sure that the main switch is initially off. Then insert a brass conductor (13mm
diameter) section intermediate section into the linear module and clamp together.
 Turn on the waater supply ensure the water flowing through the free end of the water pipe
to drain pipe to drain. This should be checked at intervals.
 Turn the heater power control knob control panel to the fully anticlockwise position and
connect the sensors leads.
 Switch on the power supply and main switch, the digital readouts will be illuminated.
 Connect the six sensor leads (T1,2,3,4,5,6,7,8,9) to the plugs on the top of the linear
conduction module. Connect the left hand sensor lead from the module to the place
marked T1 on the control panel. Repeat this procedure for the remaining five sensor lead
connecting them from left to right on the module and in numeral order on the control
panel.
 Turn the heater power control to 20 Watts and allow sufficient time for a steady state
condition to be achieved before recording the temperature at all nine sensor points and
the input power reading on the wattmeter (Q). Repeat the procedure for input power
between 10 watts. After each change, sufficient time must be allowed to achieve steady
state conditions.
 Plot the temperature, T (℃) versus distance, x (meter) calculate the actual thermal
conductivity and theoretical.

2. Observation:
Sr#
Heater
power
(W)
𝑻 𝟏
(℃)
𝑻 𝟐
(℃)
𝑻 𝟑
(℃)
𝑻 𝟒
(℃)
𝑻 𝟓
(℃)
𝑻 𝟔
(℃)
𝑻 𝟕
(℃)
𝑻 𝟖
(℃)
𝑻 𝟗
(℃)
K
(W/m℃)
1 5 44.8 44.2 43.8 43.6 33.7 27.4 27.3 27.1 26.8 375
2 10 55.4 55.3 53.4 52.5 44.7 27.5 27.4 27.3 27.1 751
3 15 74.1 71.2 70 69.4 61.2 28.1 27.9 27.6 27.3 1127
4 20 77.8 73.5 72.8 72.5 66.3 28.3 28 27.5 27.4 1538
5 25 44.8 44.2 43.8 43.6 33.7 27.4 27.3 27.1 26.8 1879
Distance
From
the
Heater
(m)
0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09
Sample Calculation:

3. Graph:
Result:
Varying the input power will affect the heat transfer coefficient. When the input power, Q(watt)
increases, the overall heat transfer coefficient, K (W/𝑚2
C) will decrease. There will be
difference between U calculated from the experiment and U calculated theoretically because of
the difference in variables (input power, area, temperature, distance and thermal conductivity)
used.