Current

[jaggers]

How do you work out the current when the only information you have is voltage and power? Can you work out the resistance from this??

[steveb]

you can use the equation

power(W)= current (i) * voltage (v).

 from this you ca then work out the resistance using the equation

voltage=current*resistance

hope that helps

[jaggers]

thanx that helps loads! wont my sci teacher b proud ... :D

[KebabMeister]

V=IR (Voltage = Current x Resistance)

Imagine a triangle.  The top of the triangle has 'V'.  Below the V is 'I' (current) in the bottom left corner and 'R' in the bottom right hand corner.  This is a little tool to help you remember how to work out whichever you require.

For example:

If you want V then the bottom of the triangle is I and R next to each other.  That means I x R = V

If you want to know what 'I' is then the V is above R.  So it's V divided by R = I

If you want to know what R is then the V is above the I so it's V divided by 'I' = R

Does that make sense?