A capacitor bank with capacity of $Q_c=30$ MVAR is designed to improve the power factor of $100kW$ to new value of $P{F}_2=0\mathrm{.}95,$ what is the value of the old power factor $P{F}_1$ is:

a$.0\mathrm{.}8466$

b$.0\mathrm{.}8025$

c$.0\mathrm{.}7875$

d$.0\mathrm{.}7520$

f$.$ none

Which of the followings is not a condition for Parallel Operation of Transformers:

a$.$ Same polarity.

B$.$ Same percentage impedance.

C$.$ Same phase sequence.

D$.$ Same voltage ratio of transformer

e$.$ none

A substation is designed according to one and half breaker swithin system includes the following circuits: $6$ transmission lines, $3$ transformers, and $1$ capacitor bank, $,$ then the total number of breakers are:

a$.9$ C$.$B

b$.10$ C$.$B

c$.15$ C$.$B

d$.20$

e