GATE EE 2018 Question Paper (10-Feb-2018) (Shift 2)

A transformer with toroidal core of permeability μ is shown in the figure. Assuming uniform flux density across the circular core cross-section of radius r R, and neglecting any leakage flux, the best estimate for the mean radius R is

A 0-1 Ampere moving iron ammeter has an internal resistance of 50 mΩ and inductance of 0.1 mH. A shunt coil is connected to extend its range to 0-10 Ampere for all operating frequencies. The time constant in milliseconds and resistance in mΩ of the shunt coil respectively are

The positive, negative and zero sequence impedances of a three-phase generator are Z₁, Z₂and Z₀ respectively. For a line-to-line fault with fault impedance Z${}_f$, the fault current is I${}_{f1}$ = kI${}_f$, where I${}_f$ is the fault current with zero fault impedance. The relation between Z${}_f$ and k is

Consider the two-bus power system network with given loads as shown in the figure. All the values shown in the figure are in per unit. The reactive power supplied by generator G₁ and G₂ are Q${}_{G1}$ and Q${}_{G2}$ respectively. The per unit values of Q${}_{G1}$, Q${}_{G2}$, and line reactive power loss (Qₗₒₛₛ) respectively are

The per-unit power output of a salient-pole generator which is connected to an infinite bus, is given by the expression, P = 1.4 sin δ + 0.15 sin 2δ, where δ is the load angle. Newton- Raphson method is used to calculate the value of δ for P = 0.8 pu. If the initial guess is 30°, then its value (in degree) at the end of the first iteration is