Shown here is a device that can be used to turn a furnace on or off, depending on the temperature sensed by the device.
-In the figure,the principle underlying the operation of this device is that
A)different metals have different latent heats.
B)different metals have different thermal conductivities.
C)different metals have different thermal expansion coefficients.
D)heat always flows from hot to cold,never from cold to hot.
E)different metals have different heat capacities.

Question

Shown here is a device that can be used to turn a furnace on or off, depending on the temperature sensed by the device. 
-In the figure,the principle underlying the operation of this device is that
A)different metals have different latent heats. 
B)different metals have different thermal conductivities. 
C)different metals have different thermal expansion coefficients. 
D)heat always flows from hot to cold,never from cold to hot. 
E)different metals have different heat capacities.

Quizplus · Accepted Answer

The device shown in the figure operates based on the principle that different metals have different thermal expansion coefficients. When the temperature changes, the bimetallic strip made of two different metals with different thermal expansion coefficients bends in one direction, causing the switch to turn the furnace on or off. This principle is utilized in many devices, including thermostats and thermal switches. The other options are not correct because they don't explain the operation of the device.

Shown Here Is a Device That Can Be Used to Turn