Write an activity to show that heat transfer in solids occurs through conduction
Answers
Answer:
Activity 1
Take a rod or flat strip of a metal, say of aluminium or iron. Fix a few small wax pieces on the rod. These pieces should be at nearly equal distances. Clamp the rod to a stand. If you do not find a stand, you can put one end of the rod in between bricks. Now, heat the other end of the rod and observe.
The process by which heat is transferred from the hotter end to the colder end of an object is known as conduction. In solids, generally, the heat is transferred by the process of conduction.
Do all substances conduct heat easily? You must have observed that the metallic pan for cooking has a plastic or wooden handle. Can you lift a hot pan by holding i t from the handle without getting hurt?
Answer:
Activity: Demonstrating Heat Transfer Through Conduction in Solids
Materials Needed:
Two metal rods of different materials (e.g., copper and aluminum)
Candle or Bunsen burner
Thermometer
Heat-resistant gloves
Stopwatch or timer
Heatproof surface or insulation pad
Procedure:
Place the heatproof surface or insulation pad on a stable table or workbench.
Put on the heat-resistant gloves for safety.
Light the candle or Bunsen burner and let it produce a steady flame.
Take the two metal rods and hold them at one end, making sure to touch only the non-heated end.
Position one end of the first metal rod (e.g., copper) in the flame of the candle or Bunsen burner, ensuring that the other end remains exposed.
Place the thermometer close to the exposed end of the first metal rod and start the stopwatch or timer.
Observe and record the initial temperature reading on the thermometer.
Allow the metal rod to heat up for a specific time interval (e.g., 5 minutes), ensuring it remains in contact with the flame.
After the designated time, quickly remove the metal rod from the flame using the heat-resistant gloves.
Immediately take the temperature reading at the exposed end of the metal rod and record it.
Repeat steps 5-10 for the second metal rod (e.g., aluminum) using the same time interval.
Compare the temperature changes in both metal rods and analyze the results.
Observations and Analysis:
During the heating process, the metal rod in contact with the flame transfers heat through conduction.
The temperature at the heated end of the metal rod should be higher than the initial temperature recorded.
The temperature at the exposed end of the metal rod should also increase, indicating the transfer of heat through conduction.
Compare the temperature changes between the two metal rods to observe how different materials conduct heat.
Generally, copper conducts heat better than aluminum, so the temperature increase at the exposed end of the copper rod should be greater than that of the aluminum rod.
Conclusion: Through this activity, you have demonstrated that heat transfer in solids occurs through conduction. The metal rod in contact with the flame conducted heat from the source to the exposed end, resulting in an increase in temperature. By comparing different materials, you can observe variations in their conductivity properties. Copper, known for its high thermal conductivity, should exhibit a more significant temperature increase compared to aluminum, which has lower thermal conductivity.
Explanation: