Voltage drop question

[user 34292]

I wonder if I could ask general past paper questions that I’m stuck on? 
 

I can’t figure out the formula that will work out the voltage drop

I’m sure it’s something simple, some help would be greatly appreciated

 

[Sharpend]

So how do you think you should approach it? 
What equations do you know that may help? 

 

[user 34292]

Could someone perhaps help me with this question. I’m sure it’s simple but I’m pretty stuck. 
 

 

[Doc Hudson]

Welcome to the forum, I have merged your two posts together that relate to the same question. Posting duplicates just clutters the forum and makes is difficult for others to follow the various topics.

re your question, your Vd calculation using the mv/a/m & length values are only useful if you know what the cable CSA is and the length of the cable run. But neither of these details have been given in the question.  Do you have a copy of guidance note 3, to read what that suggests about verifying volt-drop during a periodic inspection? You do know the resistance of the circuit conductors, and you know the current which flows through those conductors, and through the unknown size of load connected in series with the supply conductors.

Doc H.

 

[user 34292]

I had the answer there,  14.2 V

I got confused with the triangle equation. I thought I needed to divide the equation by (V) the supply voltage. 

many thanks