ok, electronics exam tomorrow, and I could do with some help on a few questions, some of this stuff ill Google, but some more input would be great.
1) what is the concept of a rotating phasor?
2) the DMM and CRO are both versatile measuring instruments. identify which instruments you would select in order to check the following signals, give reasons for your choice and comment on the value and accuracy of the instrument.
I) the a.c mains voltage
ii) a computer clock signal
iii) an audio CD pre amp output
3) A metal film resistor has a resistance of 200 ohms, when its mean temperature is 20'C calculate its resistance when its mean temperature is at 80'C
assume the temperature coefficient of resistance alpha(0) of the wire is 0.00428 per 'C, the following formula may be useful: R1 = R0 (1+alpha(0)t)
thatÂ’s it, any advice what so ever would be reallllllly helpful, thanks
1) what is the concept of a rotating phasor?
2) the DMM and CRO are both versatile measuring instruments. identify which instruments you would select in order to check the following signals, give reasons for your choice and comment on the value and accuracy of the instrument.
I) the a.c mains voltage
ii) a computer clock signal
iii) an audio CD pre amp output
3) A metal film resistor has a resistance of 200 ohms, when its mean temperature is 20'C calculate its resistance when its mean temperature is at 80'C
assume the temperature coefficient of resistance alpha(0) of the wire is 0.00428 per 'C, the following formula may be useful: R1 = R0 (1+alpha(0)t)
thatÂ’s it, any advice what so ever would be reallllllly helpful, thanks