List of top Electrical Engineering Questions asked in OJEE

The parallel RLC circuit shown in the figure is in resonance. In this circuit, 

The response of a network is $i(t) = K t e^{-\alpha t}$ for $t \ge 0$, where $\alpha$ is real and positive. The value of $t$ at which $i(t)$ will become maximum is,

The time constant of the network shown in the figure is 

In the circuit shown in the figure, $V_s = V_m \sin 2t$ and $Z = 1 - j$. The value of $C$ is chosen such that the current $I$ is in phase with $V_s$. The value of $C$ in farad is, 

What is the value of $R_C$ in the circuit at resonance? 

Determine $I_L$ by using Norton’s theorem. 

Determine $I_L$ by using Thevenin’s theorem. 

The phasor diagram of a synchronous machine connected to an infinite bus is shown in the figure below. The machine is acting as, 

If $\mathcal{L}\{f(t)\} = F(s)$, then $\mathcal{L}\{f(t - T)\}$ is equal to,
A load that has a resistance of 10 ohms is to be connected to a supply that has a constant voltage of 120 volts. If it is desired that the current to the load be varied from 3 to 5 amperes, what are the resistance and the current rating of the series rheostat that permit this variation?
To a highly inductive circuit, a small capacitance is added in series. The angle between voltage and current will,
The power supplied to a three phase induction motor is 32 kW and stator losses are 1200 W. The slip is 5%, determine the rotor copper loss.
A 12-pole, 3-phase, 50 Hz induction motor runs at 475 rev/min. Determine the slip speed and frequency of the rotor currents.
A dc generator running at 30 rev/s generates an e.m.f. of 200 V. Determine the percentage increase in the flux per pole required to generate 250 V at 20 rev/s.
A 5000 kVA, 1100 V, 50 Hz, Y-connected 3-phase alternator has armature resistance of 0.1 $\Omega$/phase and synchronous reactance of 1.5 $\Omega$/phase. Find the generated emf per phase, power factor is unity.
If the number of poles of an alternator is increased, the generated e.m.f.
Determine the torque developed by a 350 V d.c. motor having an armature resistance of 0.5 $\Omega$ and running at 15 rev/s. The armature current is 60 A.
A 6 kVA, 100 V/500 V, single phase transformer has a secondary terminal voltage of 485.50 Volts when loaded. Determine the regulation of the transformer.
A single phase transformer is rated at 40 kVA. The transformer has full-load copper losses of 800 W and iron losses of 500 W. Determine the transformer efficiency at half full-load and 0.8 power factor.
A three-phase transformer has 600 primary turns and 150 secondary turns. If the supply voltage is 1.5 kV determine the secondary line voltage on no-load when windings are connected in delta-star.
In the measurement of power consumed by a three-phase balanced inductive load using two-wattmeter method, one of the wattmeters \( W_2 \) shows zero reading. The load power factor is
In a lead acid cell, hydrogen is liberated at
Active materials of a lead acid cell are
The gravity controlled instrument has crowded scale because current is proportional to
To avoid the cripping error in the energy meters, the discs must