1.

In the LCR circuit shown in figure unknown resistance and alternating voltage source are connected.When swith S is closed then there is a phase difference of pi/4 between current and applied voltage and voltage across resister is 100/sqrt2 V.When switch is open current and applied voltage are in same phase.Neglecting resistance of connecting wire answer the following questions : Average power consumption in the circuit when S is open:

Answer»

`2500 W`
`3000 W`
`5000 W`
`1250 W`

Solution :When SWITCH is closed
`V_(rms(applied))=100` volts
`V_(peak(applied))=100sqrt2`
When switch is open `f=1/(2pisqrt(1/(25pi)xx1/(100pi)))=50/2=25 HZ`
Resistance `R=X_(L)=X_(C)=2pifL=2Omega`
Average POWER consumption =`(100/2)^(2)2=10000/2=5000 W`


Discussion

No Comment Found

Related InterviewSolutions