THERMAL AND ELECTRICAL CONDUCTIVITY OF METAL ROD manufacturer in india

Principle and Working:

The heat conduction occurs due to the temperature difference between different locations of a body. In this setup a one-dimensional temperature gradient along a copper and aluminum rod is investigated. The quantity of heat dQ transported with time dt is a function of the cross-sectional area A and the temperature gradient dT/dx perpendicular to the surface is defined as:

dQ/dt = -? A (dT/dx) 

? is the thermal conductivity of the substance.

The electrical conductivity of a metal (Copper & Aluminum) is determined by the resistance R of the rod and its geometric dimensions (l=0.315 m, A = 4.91 x10-4 m2)

? = l/(A.R)

At room temperature T the conduction electrons in metal have a much greater mean free path than the phonons. For this reason heat conduction in metal is primarily due to the electrons. The relationship between the thermal conductivity ? and the electrical conductivity ? is established by the Wiedmann-Franz law:

?/? = L T

Where L is Lorenz number.

Experiment

• To determine the heat capacity of the calorimeter.

• To study the thermal conductivity of copper and aluminum in a constant temperature gradient.

• To determine the electrical conductivity of aluminum and copper by plotting a current-voltage characteristic curve.

Apparatus Supply:

• Conductivity rod Cu

• Conductivity rod Al

• Calorimeter Vessel

• Calorimeter Vessel with rod holder

• Laboratory jack

• Immersion heater

• Temperature sensor 4Nos.

• Three finger clamp 3Nos

• Support base 2Nos

• Support rod 2Nos.

• Bosshead 5Nos.

• Power supply 20Amp

• Micro Voltmeter

• Connecting lead 4Nos

• Glass beaker