urgent help

i am having problems working out these three questions, please can some 1 help me?

1) three point charges are situated on the x-axis of a co-ordinate system. Q1= +2.0 nC is +0.05m from the origin Q2= -3.0 nC is +0.1m from the origin Q3= -10.0 nC is -0.1m from the origin what is the total force exerted by the three charges on a fourth charge Q4=
  • 5.0 nC situated at the origin? (1 nC = 10 to the (-9)c).

2) the element of an electric fire consists of 5 m of wire of 0.5mm diameter. the resistivity of the wire at 15 oC (degrees celecus) is 1.12 x

10 (-6) ohms meter. when connected to a 240v supply the fire dissipates 2kw and the tempreture of the element is 1015oC (degrees celecus). determine the value for the mean tempreture co-effivient of resistance of the wire.

3) a simple potential dividing circut is to be used to supply 10 V to a device which draws zero current. if the supply is 100V and no more than 1 uA is to be drawn from this supply, calculate the value of the resistors in the potential dividing chain.

Reply to
irfan aziz
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in article BzlGb.3$ snipped-for-privacy@newsfep2-gui.server.ntli.net, irfan aziz at snipped-for-privacy@ntlworld.com wrote on 12/24/03 11:13 AM:

Who wants to bet me that these are not scjpp; qiestopms? I do not do school questions here. Unless I am paid obscene rates, :=(


Reply to
Repeating Rifle

I can help. First, the word "i" is always capitalized like this "I". Second, I (notice the capitalization) believe you intended to use the word "one" instead of the numeral "1". Also, the correct term is "someone" not "some one".

Last but not least, you need to do your own homework if you expect to learn anything.

I shall say "you are welcome" in advance.

Charles Perry P.E.

Reply to
Charles Perry

I should also say, that me to pass the last subject in my college (a VERY difficult one)I studied about 100 hours, without asking any help from anyone (besides the fact that no-one could help me, being a pure EE subject, I wanted to pass it on my own and didn?t know the needed vocabulary in English for possible ask of help from the group).You should study on your own, and be careful with your spelling.If someone tells you the right answer right now, it would be cheating.

-- Dimitris Tzortzakakis,Greece

Ï irfan aziz Ýãñáøå óôï ìÞíõìá óõæÞôçóçò: BzlGb.3$ snipped-for-privacy@newsfep2-gui.server.ntli.net...
Reply to
Tzortzakakis Dimitrios

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