Conduction is the transfer of heat between objects in direct contact. Heat flows from the higher temperature object to the lower temperature object through the vibration of molecules. Solids are the most conductive as molecules are tightly packed, while gases are the least conductive as molecules are farther apart. The rate of heat flow is measured in watts and the ability of a material to conduct heat is called its thermal conductivity. Thermal conductivity can be measured using a two slab guarded hot plate method which involves measuring the heat transferred through a material over time for a given temperature difference and surface area.

1. CONDUCTION

2. CONDUCTION ???
WHAT IS
Conduction is the method of transfer of heat within a body
or from one body to the other due to the transfer of heat by
molecules vibrating at their mean positions.
The bodies through which the heat transfer must be in
contact with each other. There is no actual movement of
matter while transferring heat from one location to the
other.
eg.
on stove

3. conduc ion
MAT ER
t in
SOLIDS LIQUIDS GASES
Compact packing of
atoms
More intermolecular
distance
Molecules are farther
apart
Collision is more
frequent
Collision is moderately
frequent
Collision is less
frequent
More conductive Moderately conductive Less conductive

4. HEAT
Energy that is transferred from one body to another as the
result of a difference in temperature.
RATE OF HEAT FLOW
The rate of heat flow is the amount of heat that is transferred per
unit of time in some material, usually measured in watt (joules per
second). Formula => Q/t Q = amount of
heat
t = time

5. A little bit
A measure of the ability of a material to transfer heat.
It is the heat energy transferred per unit time and per unit
surface area, divided by the temperature difference.
THERMAL CONDUCTIVITY
Numerical value of the thermal conductivity indicates
how fast heat will flow.

6. AIM
To find the thermal conductivity of a material by the two slabs guarded hot
plate method.

7. Apparatus
physical virtual
• two slabs guarded hot plate
• Stop watch
• water
vlab
Physical science
Heat & thermodynamics

8. Voltmeter
reading Ammeter
reading
Guard heater switch
Main heater switch
Temperature
indicator
Stopwatch
things
many

9. Basic Principal and Formula Used
The theory of heat transfer seeks to predict the energy
transfer that may take place between material bodies as a
result of temperature difference.
Consider one dimensional heat conduction. The rate at which.
heat is conducted through a slab of a particular material is
proportional to the area A of the slab and to the temperature
difference ΔT between its sides and inversely proportional to the
slab's thickness d.
The amount of heat Q that flows through the slab in the time t is
given by Q = ( kAΔT )
d
Q
T1 T2
d
DIAGRAM

10. THERMAL CONDUCTIVITY
k = Qd
tAΔT
THERMAL RESISTANCE
The thermal resistance R of a layer of a material of
thickness d and of thermal conductivity k is given by
R = d
k
The greater the value of R, the greater the resistance
to the flow of heat.
Unit Wm-1K-1

11. OBSERVATION
TABLE

12. CALCULATIONS
Mean temperature at the surface of the specimen on the heater side,
Mean temperature at the surface of the specimen on cold plate side,
Area of heat transfer,
Heat transferred,
d = diameter of the specimen
Δx = thickness of the specimen

13. PRECAUTION
 Surrounding temperature should be kept
constant.
 Take readings at steady state condition.
 Use the knob gently.

14. NAME - ROLL. NO.
MALAY - 19001321029
LOKESH - 19001321027
AADARSH - 19001321001
AFTAB - 19001321003