A shunt reactor of 100 MVAR is operated at 98% of its rated voltage and at 96% of its rated frequency. The reactive power absorbed by the reactor is∷

Question

Question

This question was previously asked in

ISRO (VSSC) Technical Assistant Electrical 2017 Official Paper

Answer 1

Concept:

We know that

\(Q = \frac{{{V^2}}}{{{X_L}}} = \frac{{{V^2}}}{{2\pi fL}}\)

\(\frac{{{Q_2}}}{{{Q_1}}} = {\left( {\frac{{{V_2}}}{{{V_1}}}} \right)^2} \times \left( {\frac{{{f_1}}}{{{f_2}}}} \right)\)

Calculation:

\({Q_2} = 100\;MVAR{\left[ {\frac{{0.98{V_1}}}{{{V_1}}}} \right]^2}\left[ {\frac{{{f_1}}}{{0.96{f_1}}}} \right]\)

= 100.042 MVAR