Alternating Current - Result Question 17

17. A series R-C circuit is connected to an alternating voltage source. Consider two situations:

[2015 RS]

(A) When capacitor is air filled.

(B) When capacitor is mica filled.

Current through resistor is i and voltage across capacitor is V then :

(a) Va>Vb

(c) Va=Vb

(b) ia>ib

(d) Va<Vb

Show Answer

Answer:

Correct Answer: 17. (a)

Solution:

  1. (a) For series RC circuit, capacitive reactance,

Zc=R2+(1Cω)2

Current i=VZc=VR2+(1Cω)2

Vc=iX=VR2+(1Cω)2×1Cω

Vc=V(RCω)2+1

If we fill a di-electric material like mica instead of air then capacitance C↑⇒Vc

So, Va>Vb



NCERT Chapter Video Solution

Dual Pane