By inserting a plate of dielectric material between the plates of a parallel plate capacitor at constant potential, the energy stored in the capacitor is increased five times. The dielectric constant of the material is

Energy stored by capacitor, Q = ½CV²
Dielectric constant is directly proportional to C and capacitance is proportional to the dielectrical constant

Three equal star-connected inductors take 8 kW at 0.8 power factor when connected to a 460 V three - phase 3-wire supply. If one of the inductor in phase – Y is short circuited, then the line current in phase-Y is ___ Assume RYB sequence.

Here, Y phase is shorted,
Equation of 3-phase power = √3*VL*IL*cosφ
IL = P/(√3*VL*cosφ)
= 8000/(√3*400*0.8)
= 12.55 A
Phase impedance = Vp/Ip
= 460/(√3*12.55)
= 21.16 ohm
cosφ = 0.8, So φ = 37 degree.
Here Impedance of Y phase is shorted,
So, Neutral point and Y phase at same potential,
Three line voltages are given by,
Vry = 460∟0°
Vyb = 460∟120°
Vbr = 460∟-120°
Here N and Y phase at same potential,
Ir = (460∟-120°)/(21.16∟37°)
= -21.7∟83° A
Ib = (-460∟120°)/(21.16∟37°)
= 21.7∟-157° A
Ib = -(Ir + Iy)
= -21.7∟83° + 21.7∟-157°
= 37.6∟53° A

Voltage dips cannot be caused by which of the following:

A voltage dip is a short temporary drop in the voltage magnitude in the distribution or customer's electrical system.
Common causes of voltage sags and under voltages are short circuits (faults) on the electric power system, motor starting, customer load additions and large load additions in the utility service area.
Sags can cause computers and other sensitive equipment to malfunction or simply shut off.

A thermistor is inherently suitable for temperature measurement involving

Thermistors are ideal when measuring a single point temperature that is within 50°C of ambient.
If the temperatures are excessively high or low, a thermistor will not work.
Most thermistors work best in the range between -55°C and +114°C.
Sensitivity of thermistor is high.
Span value of thermistor is low.

Replace the underlined phrase in braket grammatically and conceptually with the help of the given options. If the given sentence is correct then select the option 'The given sentence is correct'.

The new client had to pay money to initiates a account and activate their service

Determine the ohmic value of the current limiting reactor per phase external to a 30 MVA, 11 kV, 50 Hz, three phase synchronous generator which can limit the current on short circuit of 5 times the full load current. The reactance of the synchronous generator is 0.05 pu.

The ratio of full load current to short circuit current = 1/5
Xsc = j/(1/5)
External reactance required = j*((1/5) - 0.05))
= j*0.15 pu
Full load current = (30*1000)/(√3*11)
= 1574.6 A
Per unit reactance = j*0.15 = (I*Xr)/V
j*0.15 = (1574.6*Xb)/((11/√3)*1000))
= 0.60 ohm