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STD 12 -7. Alternating current — JEE STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceJEESTD 12 -7. Alternating current4 Marks
MCQ
If we decrease the frequency of the applied $A.C.$ with a purely capacitive load, do $(1)$ the amplitude of $V_c$ and $(2)$ amplitude of $I_c$ increase, decrease of remain the same.
  • A
    $(1)$ increase $(2)$ same
  • B
    $(1)$ same $(2)$ increase
  • ✓
    $(1)$ same $(2)$ decrease
  • D
    $(1)$ decrease $(2)$ same
✓

Answer

Correct option: C.
$(1)$ same $(2)$ decrease
c
${X_c} = \frac{1}{{\omega _c\,}}$ and ${i_c} = \frac{{V_c}}{{X_c\,}}$

With decrease in frequency, $X_c$ increases and hence $i_c$ decreases.

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