Q6. A 318 uF capacitor is connected to 200V, 50 Hz supply. Determine a)=♡ I LOVE MY PRINCESS ♡capacitive reactance b) maximum current c) rms value of current. Write the expressions for voltage and current.
Answers
Answer:
A 318uF capacitor is connected across 230V, 50Hz system. Determine i) Capacitive reactance (3 marks) ii) Root mean square value of current (2 marks) iii) Equation for voltage and current (6 marks) (b) In the circuit below a p.d., V is applied across a capacitor and its value at a time to is given by V=Vo sin wt, where Vo is its peak voltage and o=2rt f where f is the frequency of the source Show that the capacitance reactance is given by Xc=1/2rfc (5 Marks) (c) Capacitances of 3 uF, 6 uF and 12 uF are connected in series across a 350 V supply. Calculate i) The equivalent circuit capacitance, ii) The charge on each capacitor and, iii) The pd across each capacitor.
Given:
318 uF capacitor
200V, 50 Hz supply
To find:
a) capacitive reactance
b) maximum current
c) RMS value of current
d) expressions for voltage and current
Solution:
a) Capacitive reactance = Xc = 1/ 2 π f C
= 1 / 2 X π X 50 X 318 X 10⁻⁶
= 1/318 π X 10⁻⁴
= 10Ω
b) Max Current = I = V/Xc
= 200/10
= 20A
c) I rms = I max / √2
= 20 / √2
= 10 √2
= 14.1 A
d) Volatge = Current X Impedence
Current = Volatge / Impedance