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Trying to prove a point
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Brutte:
The switch stays NO "normally open" no matter if you actuate it or not. It is a property of a switch and not its (electrical) state. So if you actuate a NO switch, the switch is still "normally open", although the switch starts conducting.
Mechatrommer:

--- Quote from: brabus on June 07, 2019, 09:11:08 am ---No relay is mentioned, so a "switch" can be any manually activated switch, or a relay as well. The question only says "electrical state of the switch contacts".

--- End quote ---
manually actuated switches such as toggle switches, DPDT SPDT etc dont usually specified as NO nor NC. non-latched or returning switches are seldomly in use. so anyway, there are many type of switches, the person who made this question should take this into consideration. C is possible as well as D. the OP should also ask the teacher why it cant be D to understand his rational.
Rerouter:
When ever I feel like a question is ambiguous I just write my assumptions next to the answer,

Another Agreeing with D as the most correct answer given the assumptions, for the next one, a solar panel would be the most correct, as its the device generally used for that purpose. e.g. the lay person answer.

Back when I was studying electricity in TAFE, There where a few tests where the teacher had obviously had his own go at rewording or answer flipping the reference test to try and catch people who found a copy of the previous years one, sadly he introduced a ton of typos and made some things really hard to answer,

I did win him over to revising the next years test with my suggestions, but that was more or less earned respect, as I tried to not be a dick about it, and he knew I was smart on the topic,

Best memory of that class was creating a washing machine ladder-logic solution, I solved it in about 4 minutes, had 30 minutes to do it, so iterated it down to the least relays and function blocks possible, It for one flagged any other student that had (tried to) copied me, and left the teacher needing to simulate the thing to make sure it worked as he could not follow it. was a fun task,
LateLesley:
Another vote for D.

They label the "Normal" positions when the switch isn't activated. So NC will connect to common (C) , and NO will be floating. Once the switch is operated, the NC is disconnected, and NO is connected to common.

Look at page 2 of this datasheet. http://www.farnell.com/datasheets/1702886.pdf

EDIT : And as applies to Relays- https://circuitdigest.com/article/relay-working-types-operation-applications

2nd EDIT : "In schematics switches are always drawn in the OFF position." http://www.zen22142.zen.co.uk/Prac/relay.htm
Nominal Animal:
CoopedUp: If I were you, I'd find a SPDT switch with NO and NC markings (any common microswitch, or say a wall-mounted light switch), and show it to the teacher:


These markings only make sense on an electrical switch when NO and NC represent the state when the switch is not actuated.  Whether there is current flowing/power applied or not, has nothing to do with the switch (unless the power is enough to break the switch); the switch controls the electrical connection. Thus, D is the correct answer.

Someone mentioned relays; they too have NO and NC markings:

However, for a relay, "actuated" state == "energized" state == "when power is applied" to the relay coil; and "normal" state is when there is no power applied to the relay coil.

Whether there is current flowing over the NO/NC pins or not, is irrelevant.  So, D is definitely still correct; C (power is not applied) is only correct if we amend the "when power is not applied" with "to the relay coil".  Otherwise there is ambiguity in where power is applied with respect to the relay.

In every single case, whether power is conducted through the connection controlled by the switch or relay, is completely irrelevant.

My instincts say that your teacher is in error, because they are fixated on looking at things from the point of view of controlling the current/power, instead of controlling the electrical connection.  If I were you, I'd start my objection with something like "that might make sense if you looked at from the point of view of controlling the current/power, but in reality, a switch controls the electrical connection, and not the current or power conducted through the connection", followed by the images and text above.


We need to learn how correct the utterance or writing, instead of the person making it, because you are at a common task, not adversaries.

This sounds silly social games, but it is important nevertheless.  It means you acknowledge that perhaps the person isn't wrong, and is simply expressing themselves poorly.  It means that you do not question their knowledge, simply the way they express it.  Mis-expressing stuff is, in my experience, much more common than being straight-out wrong, at least when talking with professionals.

That approach to error-correcting is fortunately very contagious, and rapidly spreads: we feel better when our output is criticized and made better, without criticising us ourselves as a person.  It also helps the lecturer, as correcting errors have much less impact on ones self-esteem, as it is questioning the way things are put, rather than the knowledge it stems from.  I've been on both sides (student and lecturer), and it definitely works well for me.

This is also why I use a pseudonym on the intertubes: it reminds me that any and all criticism is based on my work product, and has nothing to do with me as a person, as none who use that pseudonym know me socially.  (As a self-broken husk of a man, I need that sort of a social crutch.)
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