(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

This question is about the heated front windscreen of a car

The heater consists of resistance wires which are embedded in the glass

A) The power of the heater needs to be 180W for a satisfactory demisting

A car battery of Negligable internal resistance supplies 12V to operate on the heated screen

Calculate the current required to deliver a power of 180W

180/12=15A

Show that the resistance of the heater when operating is about 1ohm

12/15=0.8 ohms, rounded up=1ohm

B) the heater consists of 200 wires inside the glass

These wires are connected in parallel to the 12V supply

Each of the 200 wires has a length of 0.70m and a resistance R(subscript)p of 160 ohms

The material of the wire has resistivity p=6.0x10^-7ohmic metres

Calculate the DIAMETER of the wire

please people, I don't want the answer, can someone just help me out and give me the equation I need to use? I'm terrible at remembering equations I really need the equation, thanks x

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# Homework Help: Diameter of a wire with length, resistance and resistivity

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