For the series LCR circuit connected with 220 V, 50 Hz a.c. source as shown in the figure, the power factor is α10. The value of α is ________. [2026]
(4)
Power factor=RZ
Z=R2+(XL-XC)2
=602+(150-70)2=100 Ω
∴ Power factor=60100=610
Then a=6