DC Power Measurement
Trending Questions
Q. A dc A-h meter is rated for 15 A, 250 V. The meter constant is 14.4 A-sec/rev. The meter constant at rated voltage may be expressed as
- 3750 rev/kWh
- 3600 rev/kWh
- 1000 rev/kWh
- 960 rev/kWh
Q. For the circuit in the figure, the voltage and current expressions are:
v(t)=E1sin(ωt)+E3sin(3ωt)
and i(t)=I1sin(ωt−ϕ1)+I3sin(3ωt−ϕ3)+I5sin(5ωt)
The average power measured by the Wattmeter is
v(t)=E1sin(ωt)+E3sin(3ωt)
and i(t)=I1sin(ωt−ϕ1)+I3sin(3ωt−ϕ3)+I5sin(5ωt)
The average power measured by the Wattmeter is
- 12E1I1cosϕ1
- 12[E1I1cosϕ1+E1I3cosϕ3+E1I5]
- 12[E1I1cosϕ1+E3I3cosϕ3]
- 12[E1I1cosϕ1+E3I1cosϕ1]