# Recent questions and answers in Capacitor

The reactance offered by a capacitor to an alternating current of frequency 50 Hz is 10 ohm. If frequency is increased to 100 Hz, the reactance will be (a) 2.5 ohm (b) 5.0 ohm (c) 20.0 ohm (d) 40.0 ohm

How will the total capacitance change, when two capacitors are connected in parallel?

A capacitor used for power factor correction in single phase circuit decreases: (1) Power factor (2) Line current (3) Both line current and p.f. (4) The line current and increases p.f.

Which of the following capacitors are used in D.C. circuits ? (a) Mica (b) Air (c) Ceramic (d) Electrolytic

Piezoelectric effect is generally observed in (a) conductors and super conductors (b) conductors and semi conductors (c) insulators (d) insulators and conductors

In a parallel plate capacitor of capacitance Co, the electric field is E. If a dielectric slab with dielectric constant = 7 is introduced to fill capacitor completely, the electric field will become (a) 7E (b) E/7 (c) E/3.5 (d) E. Co

A capacitor opposes:

If the output filter capacitor in a power supply actually had a value twice its stated value, which of the following symptoms would be found?   a. The output voltage would be doubled and a small improvement in the ripple voltage would be detected.  b. The ripple voltage would be half of what is expected and a ... output voltage would be detected.  c. The output and ripple voltage would be greater than expected.  d. The output and ripple voltage would be less than expected.

For a parallel plate capacitor which is being charged out of the following the incorrect statement is   (A) Energy stored in the capacitor does not enter it through the connecting wire through the space around the wires and plates of capacitor.   (B) Rate at which energy flows into this volume is equal ... poynting vector points everywhere radially outward of the volume between plates.   (D) The poynting vector points everywhere radially in to the volume between the plates.

Modern capacitors which have high capacitance in small size use a dielectric of   (A) paper (B) rubber (C) ceramic (D) Mylar