Video Transcript
Which of the following is the
correct circuit symbol for a resistor with a fixed value? Is it option (A), (B), (C), (D), or
(E)?
The question is asking for the
symbol of a resistor with a fixed value, meaning not a variable resistor, but a
resistor that has a constant resistance. Let’s look at the different symbols
given and identify them. The first symbol in option (A) has
a zigzag shape, and it also has an arrow that crosses it. This is the symbol for a variable
resistor, that is, a resistor whose resistance can change and is not fixed. It is often adjusted by turning a
knob or using a slider. If it helps us to remember the
symbol, we might like to think of the zigzag as representing a wire with high
resistance that has been wrapped around a ceramic tube. And when we look at it from the
side, it looks like a zigzag. We can think of the arrow as
representing a resistance that can be changed.
The second symbol in option (B)
corresponds to a buzzer, which is a connected half circle. To remember this symbol, we could
imagine the top flat edge as the buzzer symbol vibrating to create a buzzing noise
by creating sound waves in the surrounding air. The symbol in option (C) is an X
inside a circle, and this indicates that it is a bulb. We can imagine the circle as the
glass bulb, with the X representing the glowing filament inside.
The symbol in option (D) is a
zigzag, and as we know already, this is a resistor. Without the arrow we saw previously
in option (A), this means it has a fixed resistance that does not change. The symbol in option (E) represents
electrical power cells that are connected by a dashed line. This indicates that there are two
or more cells connected to form a battery.
Thus, we’ve seen that the correct
answer is option (D). This shows the symbol for a
resistor with a fixed value.