Voltage drops - i don't understand

[debwaldy]

Homework Statement

Hi, this question is really confusing me and preventing me from completing the rest of the question. It is probably a very simple problem but i just don't understand so any help would be much appreciated.

A metal- filament lamp,rated at 750W, 100V, is to be connected in series with a capacitor across a 230V, 50Hz supply. Calculate the voltage drop across the capacitance required, the current, the capacitance, phase angle between the supply voltage and current.

Homework Equations

P = IV
V=IX X = capacitive reactance

The Attempt at a Solution

I think the current is given by
I = 750W/100V?
I don't know how to calculate the voltage drop.Thanks for any help and tips
Debs

 

[marcusl]

The voltage drop needed across the capacitor to keep the bulb happy is 230 - 100 = 130V. To find the capacitance, look for a capacitor equation relating the voltage to the rate of change of the current (it will involve the frequency).