A balanced delta connected load of 8+j6 Ω per phase is connected to a 415 V, 50 Hz, 3-phase supply lines. If the input power factor is improved to 0.9 by connecting a star connected capacitor bank, then the required kVAR of the bank is

Current flow through the circuit,
I = V/Z
= 400/10
= 41.5 A
Power factor = 8/10
= 0.8
After connecting a capacitor bank, the reactive power component of current changes but the active power component of current is unchanged.
I1*cosφ1 = I2*cosφ2
41.5*0.8 = I2*0.9
I2 = 36.88 A
Q1 (before connecting capacitor) = √3*VL*IL*sinφ1
= √3*415*41.5*sin(36.86)
= 26.847 kVAR
Q2 (after connecting capacitor) = √3*VL*IL*sinφ2
= √3*415*36.88*sin(25.84)
= 15.867 kVAR
kVAR supplied by capacitor bank = Q1 - Q2
= 26.847 - 15.867
= 10.98 kVAR

Murray loop test is performed on a faulty cable 300 m long. At balance, the resistance connected to the faulty core was set at 15 Ω and the resistance of the resistor connected to the sound core was 45 Ω. Calculate the distance of the fault point from the test end.

Where,
R2 is the resistance connected to the faulty core in ohm
R2 is the resistance of the resistor connected to the sound core in ohm

R1 Distance of fault location (Lx) = R2/(R1 + R2)*(2*L)
= (15/60)*600
= 150 m

Two-wattmeter method is used to measure the power taken by a 3-phase induction motor on no load. The wattmeter readings are 375 W and –50 W. Calculate the reactive power taken by the load.

Reactive power taken, Q = √3*(W1 - W2)
Q = √3*(375 + 50)
Q = √3*425 kVAR

Which of the following is the layer of a computer system between the hardware and the user program?

In underground cables, the electrostatic stress is ___ at contactor surface and ___ at the sheath.

The electrostatic stress in a cable is not uniformly distributed.
The potential gradient is inversely proportional to the distance from the centre of the cable.
Hence, it will be maximum (gmax) at the surface of the conductor and goes on decreasing until it becomes minimum (gmin) at the surface of the sheath.
That means electrostatic stress in the dielectric of a cable is maximum at the surface of the conductor and minimum at the surface of the sheath.

A new generation of smart meters is known as ____

The second generation of smart meters are known as SMETS 2.
Full form of SMET is Smart Metering Equipment Technical Specifications.
It is with the previous generation known as SMETS 1.
SMETS 2 smart meters were introduced in 2018.