Needing help with a past paper question- full scale deflection or something?

Hi, I'm doing OCR B advancing physics and I'm stuck on this certain type of question.

Could anyone explain to me what exactly I'm meant to be looking for in these questions? They just really confuse me and this format seems to come up a lot. Thanks for any help!

Reply 1

Morbo

The question wording of "the" temperature sensor leads me to believe there is more to this question than you are giving us. In order to decide which of these meters is the best, we need to know things about the sensor e.g. its resistance range.

Reply 2

Human Being

Oh yeah, sorry!! Here's the other information you get:

Reply 3

Morbo

Whatever you're using to measure the voltage across the sensor has to be able to deal with the full range of voltages the sensor can produce, and also be sensitive enough to give a reasonable resolution within this range.

The voltmeter's not an option because it's max. voltage is 0.2mV, and we need readings above this.

Now, the CRT gives 1.0mV mm^-1. This means your full range of readings takes up less than 1mm, which is frankly impossible to see any detail. The moving coil on the other hand will give you 0-100 degrees C in about 600mm. Even though the full-scale deflection is less than this, it's the only option that allows you to see enough resolution.

Reply 4

Human Being

Thankyou thankyou thankyou! It makes sense now.

I would rep you but I think I'm worthless..

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