The single line diagram of the simple system is shown in figure the corresponding reactance diagram is

Simple logic of reactance diagram is that simplified equivalent circuit of power system in which the various components of power system are represented by their reactance.
The reactance diagram can be obtained from impedance diagram if all the resistive components are neglected.
So, from figure each of the component is represented by its reactance.

An electric potential field is produced in air by point 1 μC and 4 μC located at (-2, 1, 5) and (1, 3, -1) respectively. The energy stored in the field is

Fill in the blanks with suitable Article from the given alternatives.
Bread is ___ predominant food prepared from a dough of flour and water

___ is the short time reduction in the rms voltage between 0.1 to 0.9 p.u for a duration of ___

Voltage sag:
It is usually associated with system faults but can also be caused by energization of heavy loads or starting of large motors.
Voltage sag is the short reduction in the RMS voltage between 0.1 to 0.9 pu for a duration of 0.5 cycle to 1 minute

Which type of connection is employed for current transformers for the protection of delta- star connected 3-phase transformer?

The connection of CT on primary and secondary side is always reverse to the connection of transformer.
To protect the power transformer with star-delta against fault, the type of connection of CTs should be in the delta–star connection otherwise the relay will operate when an external fault occurs due to zero sequence currents

Calculate the capacitance per meter of a 50 Ω load cable that has an inductance of 50 nH/m.

Z = √(L/C)
C = L/Z²
C = 50*10⁻⁹/(50*50)
C = 0.02 nF
C = 20 pF