Recent questions in Electrical Machines

The figure shows the per-phase equivalent circuit of a two-pole three-phase induction motor operating at $50$ Hz. The “air-gap” voltage, $V_{g}$ across the magnetizing in...

A shunt-connected $DC$ motor operates at its rated terminal voltage. Its no-load speed is $200$ radian/second. At its rated torque of $500$ Nm, its speed is $180$ radian/...

Match the following:$\begin{array}{|l|l|l|l|} \hline & \textbf{Instrument Type} & & \textbf{Used for} \\ \hline P. & \text{Permanent magnet moving coil} & 1. & \text{DC...

A DC motor has the following specifications: $10$ hp, $37.5$ A, $230$ V; flux/pole $= 0.01$ Wb, number of poles $= 4$, number of conductors $= 666$, number of parallel pa...

A separately excited $DC$ motor runs at $1000$ rpm on no load when its armature terminals are connected to a $200$V DC source and the rated voltage is applied to the fiel...

A $3$-phase $50$ Hz square wave ($6$-step) VSI feeds a $3$-phase, $4$ pole induction motor. The VSI line voltage has a dominant $5^{th}$ harmonic component. If the operat...

A separately excited $DC$ generator has an armature resistance of $0.1 \Omega$ and negligible armature inductance. At rated field current and rated rotor speed, its open-...

The starting line current of a $415$ V, $3$-phase, delta connected induction motor is $120$ A, when the rated voltage is applied to its stator winding. The starting line ...

The direction of rotation of a single-phase capacitor run induction motor is reversed byInterchanging the terminals of the AC supply.Interchanging the terminals of the ca...

A $50$ MVA, $10$ kV, $50$ Hz, star-connected, unloaded three-phase alternator has a synchronous reactance of $1$ p.u. and a sub-transient reactance of $0.2$ p.u. If a $3$...

The following figure shows the connection of an ideal transformer with primary to secondary turns ratio of $1:100$. The applied primary voltage is $100 V$ (rms), $50 Hz, ...

A three-phase, $50 Hz$ salient-pole synchronous motor has a per-phase direct-axis reactance $(X_{d})$ of $0.8$ pu and a per-phase quadrature-axis reactance $(X_{q})$ of $...

A $DC$ shunt generator delivers $45 A$ at a terminal voltage of $220 V$. The armature and the shunt field resistances are $0.01 \Omega$ and $44 \Omega$ respectively. The ...

A single-phase $400 V, 50 Hz$ transformer has an iron loss of $5000 W$ at the rated condition. When operated at $200 V, 25 Hz$, the iron loss is $2000 W$. When operated a...

A $4$-pole, lap-connected, separately excited $dc$ motor is drawing a steady current of $40$ A while running at $600$ rpm. A good approximation for the waveshape of the c...

If an ideal transformer has an inductive load element at port $2$ as shown in the figure below, the equivalent inductance at port $1$ is$nL \\$$n^{2}L \\$$\dfrac{n}{L} \\...

In a constant $V/f$ induction motor drive, the slip at the maximum torqueIs directly proportional to the synchronous speed.Remains constant with respect to the synchronou...