EE MCQ

MGVCL Exam Paper (30-07-2021 Shift 2)
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A circular loop has its radius increasing at a rate of 2 m/s. The loop is placed perpendicular to a constant magnetic field of 0.1 Wb/m². When the radius of the loop is 2 m, the emf induced in the loop will be

emf = dΨ/dt = change of flux linkage

emf = dф/dt

emf = d(B*Area)/dt

emf = B*d(area)/dt

emf = B*d(πr²)/dt

emf = Bπ*2r*dr/dt

emf = Bπ*2r*change of radius per unit time

emf = 0.1*π*2*2

emf = 4π

Related Question

MGVCL Exam Paper (30-07-2021 Shift 2)
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The expression for voltage regulation of a short transmission line for leading power factor is given by: ____, where, 'I' is the line current, 'V_r' is the receiving end voltage, 'R' is the line resitance and 'X' is the line reactance.

For lagging power factor = (IR*cosφ + IXsinφ)/V_r

For leading power factor = (IR*cosφ - IXsinφ)/V_r

Zero voltage regulation occurs on leading power factor only.

MGVCL Exam Paper (30-07-2021 Shift 2)
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The necessary equation to be solved during the load flow analysis using Fast-Decoupled method is given below:

where B' and B'' are formed using the imaginary part of the bus admittance matrix, Ybus. If the system consists of 6 buses of which one of the bus is slack bus and 2 bues are voltage regulated buses, then then the matrix B' is of order ____and the matrix B'' is of order____, respectivity.

∆P/|Vi| = - B'∆δ

∆Q/|Vi| = - B''∆|V|

where B' and B'' are formed using the imaginary part of the bus admittance matrix, Ybus. If the system consists of 6 buses of which one of the bus is slack bus and 2 bues are voltage regulated buses, then then the matrix B' is of order ____and the matrix B'' is of order____, respectivity.

∆P/|Vi| = - B'∆δ

∆Q/|Vi| = - B''∆|V|

In Fast-decoupled method,

Order of B' = No. of PV buses = 5

Order of B'' = No. of PQ buses = 3

MGVCL Exam Paper (30-07-2021 Shift 2)
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In circuit breaker, the term MCCB stands for

MCCB stands for Moulded Case Circuit Breaker.

MCB stands for Miniature Circuit Breaker.

ELCB stands for Earth Leakage Circuit Breaker

RCCB stands for Residual Current Circuit Breaker.

MGVCL Exam Paper (30-07-2021 Shift 2)
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In the circuit of figure, the switch is closed to position-1 for a long time. At t = 0 the switch position is changed from postion-1 to postion-2. Find an expression for the current i(t).

Standard eqution of current for this condition,

i(t) = i(0+)*cos(wt)

i(0+) = E/R

For LC circuit,

w = 1/√(LC)

i(t) = (E/R)*cos((1/√(LC))*t) A