Passage V
Heat conduction is a process by which heat is transferred from a region at a higher temperature to a region at a lower temperature. Two regions that are in thermal equilibrium with each other are at the same temperature. No heat is transferred between regions in thermal equilibrium with each other.
A student studied the relationship between the length and diameter of a copper wire connecting 2 metallic blocks and the rate of heat conduction between the blocks.
Experiment 1
A small aluminum block, A, was heated to 100℃ in boiling water, and an identical aluminum block, B, was cooled to 0℃ in ice water. Both blocks were immediately placed on an insulating surface (a surface that does not conduct heat well) and connected by a given length of 1 mm diameter copper wire initially at room temperature so that the wire would conduct heat from Block A to Block B (see Figure 1).
The temperature of each block was measured at regular time intervals for 3 minutes. The same procedure was done with different lengths of 1 mm diameter copper wire. The results are shown in Table 1.
Experiment 2
The procedure described in Experiment 1 was repeated using a copper wire with a diameter of 1.4 mm. The results are shown in Table 2.
26. During Experiments 1 and 2, the 2 blocks reached thermal equilibrium when which of the following copper wires was used?
Your Answer is
Correct Answer is H
Explanation
Thermal equilibrium means that the temperature of two objects will eventually be the same.
Looking at table 1 & table 2, only in the group where the length of wire in table 2 is 10 cm (diameter is 1.4 mm), Blocks A & B have the same temperature after 3 minutes It is 40°C