EE MCQ

MGVCL Exam Paper (30-07-2021 Shift 1)
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While selecting the gas for a circuit breaker, the property of gas that should be considered is its

(i) dielectric strength

(ii) non-inflammability

(iii) non-toxicity

(i) dielectric strength

(ii) non-inflammability

(iii) non-toxicity

Properties of gas while selecting circuit breaker,

1. Dielectric strength.

2. Thermal conductivity.

3. Arc quenching.

4. Electrical properties.

5. Chemical properties.
Toxicity of arc products.

Related Question

MGVCL Exam Paper (30-07-2021 Shift 1)
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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.

MGVCL Exam Paper (30-07-2021 Shift 1)
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The necessary equation to be solved during the load flow analysis using Fast-Decoupled methid is given below:

where B' and B'' are formed using the imaginary part of the bus admittance matrix Ybus, n is the total number of buses in the system, m is the number of voltage regulated buses. The size of matrix B' is

∆P/|Vi|= -B' ∆δ

∆Q/|Vi| = -B'' ∆|Vi|

where B' and B'' are formed using the imaginary part of the bus admittance matrix Ybus, n is the total number of buses in the system, m is the number of voltage regulated buses. The size of matrix B' is

∆P/|Vi|= -B' ∆δ

∆Q/|Vi| = -B'' ∆|Vi|

In FDLF method,

B' corresponds to susceptance of unknown of PQ and PV bus

Order of B' matrix is = (n -1)*(n - 1)

Where n is total no. of buses.

Order of B'' = (n - m - 1)*(n - m - 1)