Discussion in 'Homework Help' started by bujak18, Jan 14, 2009.
what is the reactance of a .22uf, 250v capacitor at 400Hz?
Are you familiar with the laplace transform? If not, here is a walk through to get the reactance of a capacitor:
For a capacitor
i = C * dv/dt
v = 1/C * integral(i, 0 , t) + V0.
Now the laplace transform is defined as follows
I(s) = integral(i(t) * exp(-s*t), 0, inf)
Now the cool thing is, if we integrate I(t) prior to performing the laplace transform we will get
i2(t) = integral(i(t))
I2(s) = I(s)/s
Applying this rule to our formula for v we get
V(s) = 1/(C*s)*I(s).
the reactance is just the imaginary part of the resistance of a component,
therefore the reactance is:
Whilst Santa is busy stuffing is, js and ks into next years christmas stockings it may be worth noting that the reactance is given by
X = 1/2π f C
i.e. = 1/(2πx400x2.2 x10) ohms
The voltage rating of the capacitor or the applied voltage is immaterial.
does anyone know the exact answer? pls
can u simplify this? pls
bujak18, I think that what these guys wrote is as simple as it gets.
They took the definition of capacitive reactance, plugged in your values and gave you the answer.
nm i figured it out thanks guys my cousin was typing that hes 14 sry!