Question

checkpoints
check your understanding
figure 21: this conceptual model shows the basics of
how a dryer works.
diagram of dryer system with timer, heating elements, clothes, sensor, feedback loop, electrical energy, desired time (input), heat (output), actual dryness
use the diagram to answer the next three questions.

1. how does the sensor interact with the other

components of this system?
○ a. the sensor detects the heat of the clothes
and makes the timer generate more heat.
○ b. the sensor detects the dryness of the clothes
and then sends information to the timer.
○ c. the sensor detects whether the heating
element is functioning properly and then
sends input to the timer.
○ d. the sensor detects how much time is
left and sends input to the heating element to
increase or decrease the heat.

1. select the correct term to complete the statement.

the model of the dryer system represents a(n)
open | closed | isolated system because energy
enters in the form of heat | electricity and exits in
the form of heat | electricity, but matter contained
in the dryer, such as the metal casing and electrical
wiring, enter and exit | remain in | are often
removed from the system

1. what is

○ a. a
in
○ b. a
○ c.
○ d

1. pic

atn
an
in
th
in
c

Explanation:

Question 1

To solve this, we analyze each option using the diagram:

• Option a: The timer doesn't generate heat (heating elements do), so a is wrong.
• Option b: The diagram shows the sensor detects dryness (actual dryness feedback) and sends error (information) to the timer. This matches.
• Option c: The sensor is connected to clothes (dryness), not heating element functionality, so c is wrong.
• Option d: The timer deals with time, and the sensor doesn't detect time left. So d is wrong.

1. System Type: A closed system allows energy transfer but not matter (or minimal matter) transfer. The dryer has energy (electricity in, heat out) but matter (metal, wiring) stays. So "closed".
2. Energy In: The diagram shows "electrical energy" input, so energy enters as "electricity".
3. Energy Out: Heating elements produce heat, so energy exits as "heat".
4. Matter: The metal casing and wiring are part of the dryer and don't enter/exit, so "remain in".

Answer:

b. The sensor detects the dryness of the clothes and then sends information to the timer.

Question 2