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Elka
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Homework Statement
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