GATE EE 2016 Question Paper (06-Feb-2016) (Shift 2)

A single-phase $400V,50Hz$ transformer has an iron loss of $5000W$ at the rated condition. When operated at $200V,25Hz$, the iron loss is $2000W$. When operated at $416V,52Hz$, the value of the hysteresis loss divided by the eddy current loss is ______.

A DC shunt generator delivers $45A$ at a terminal voltage of $220V$. The armature and the shunt field resistances are $0.01\Omega and44\Omega$ respectively. The stray losses are $375W$. The percentage efficiency of the DC generator is ____________.

A three-phase, $50Hz$ salient-pole synchronous motor has a per-phase direct-axis reactance $\left(X_d\right)$ of $0.8pu$ and a per-phase quadrature-axis reactance $\left(X_q\right)$ of $0.6pu$. Resistance of the machine is negligible. It is drawing full-load current at 0.8 pf (leading). When the terminal voltage is $1pu$, per-phase induced voltage, in $pu$, is _________.

A single-phase, 22 kVA, 2200/220 V, 50 Hz, distribution transformer is to be connected as an auto-transformer to get an output voltage of 2420 V. Its maximum kVA rating as an auto-transformer is

A single-phase full-bridge voltage source inverter (VSI) is fed from a $300V$ battery. A pulse of $120^o$ duration is used to trigger the appropriate devices in each half-cycle. The rms value of the fundamental component of the output voltage, in volts, is