SSC JE Electrical Engineering 2012
For the following questions answer them individually
The rms of the alternating current given by the equation $$i = 50 \sin (314t - 10^\circ t) + 30 \sin (314t - 20^\circ)$$ is
In a balanced 3-phase system, the current coil of a wattmeter is inserted in line 1 and the potential coil across 2 and 3. If the wattmeter reads 100 W, the reactive power drawn by the 3-phase load is
A non-sinusoidal periodic waveform is free from DC component, cosine components and even harmonics. The waveform has
A periodic train of rectangular pulses x(t) with a time period of 25 seconds, has a pulse width of 9 seconds as shown in figure. The RMS value of the waveform is
In the series RC circuit, the voltage across C starts increasing, the moment the circuit is switched to V volts DC. The rate of increase of voltage across C at the instant just after the switch is closed (i.e. at $$t = 0^{+}$$) is
The phase difference between the following voltage and current waves $$v = 311 \sin (100 \pi t + 30^\circ)$$ Volts $$i = 17 \sin (100 \pi t - 20^\circ)$$ Amps is
