help needed with 17th edition please

[i=p/u]

i have few 17th exam papers in front of me.. well as it says external, i would be drawn straight to A as is outside.. external influences=ip44... or there abouts

 

[1983]

lol no need for vd as that was the only question but if i wanted to cal vd it b mv/a/m x l x ib/1000. say the L was 10m would vd be 1.43v?

 

[Marnik]

you don't need to know thength to calculate the voltage drop of a circuit!
The simple formula ; r1 + rn x 1.2 x Ib = vd

 

[i=p/u]

wheres 1.2 come from if you dont mind me asking, isit operating tempeture,

 

[Marnik]

correct i=p/u . it is indeed the operating temperature correcting factor.

 

[i=p/u]

so when would you do this adding of 1.2 in the real working world, if you have we example

you don't need to know thength to calculate the voltage drop of a circuit!
The simple formula ; r1 + rn x 1.2 x Ib = vd

 

[i=p/u]

i just know IxR=V

 

[telectrix]

well that's what he means . V ( volt drop) = I x R, where R is R1+R2, then correct for temp. with the 1.2 factor.

 

[i=p/u]

what reg is this telectrix? so when would you use this, would you just not measure it, give you awnser ... or is this when designing