Answer / sanjay dalvi

power factor of DC system is allways 1,why??
in DC POWER SUPPLY a power supply is constant in nature,
p=v*i angle between voltage & current is zero that is
current is in phase with voltage, cos$=0
for dc supply $ =0
& we know that cos 0 =1
so we can proove that cos $ =1 hence
p= V I COS$
P= V I KW

Answer / k.prakashchandra

unity

Answer / kesavan.03

Power Factor is nothingbut the phase angle between Voltage
& Current. In AC System power factor will be lag & lead
system due to its nature of wave form & phase angle
difference.

As in the case of DC System there is no power factor term
is used because DC System has constant voltage & Current..
So phase difference is zero.

Power = V x I x cosØ

for DC System cosØ = 1 ( Ø = 0 degree)

Since cos 0 = 1

Answer / eng.ahmad

the power factoe is 1 in dc system if tehere is no ripple.
for example if you test the pf of battery charger you will
find it less than 1 because of the ripple, and you can
solve this problem by using coil (chock).

eng.ahmad from iraq

Answer / t swetha

powerfactor of dc supply is 1 why because there is no phase
difference between the voltage and current

Answer / fazul

In a.c system current and voltage are lag or lead according
to the inductance or capacitance.
but in d.c system current and voltages are inphase with each
other.so phase angle between current and voltage is zero.
we know p.f=cosO
p.f=1

Answer / aye thwin

1) Assuming DC supply is pure DC or constant, if load current is pure dc current, it is power factor=1, if not pf <1.
2) For DC system, should not use cos value which is related to ac system.
3) Power factor is not only relative to reactive power , but also need to consider the distortion power which is related to harmonic.

Answer / sakthivel

in dc system voltage and current are in phase so here no
power factor

Answer / naagaraju badara

In dc capacitor acts as o.c and inductor as s.c and in pure resistor angle b/w v&i is zero hence it will be unity always

Is it possible to increasing the real power generation by reducing the reactive power in power generation plants

3 Answers  

1 “earthing” for bonding of equipment and circuits to common plant earth electrode potential, 2 “protective earthing (PE)” when this bonding is required for personal safety provisions 3 “grounding” for interference suppressing bonding of screens, sys-tems with ground level 4. low-impedance earthing ? 5.primary earthing system and secondary earthing system what is that? 6.earthing electrode or mesh net earthing electrode ? very confusing , simple but very informative help required ? i will be very very thankful to you guys.

0 Answers   ABC,

How can we measure the frequency of a rotor running in full load condition? Explain the method of measuring.

2 Answers   Wipro,

what is the formulae for calculating the cable size for a given voltage and current.

4 Answers   Bharat Forge,

i need to now what will be the cable size to the following load, transformer to distribution panel distance 110m, load 1000kw, voltage 400v, pf 0.85, permissible voltage drop 2.0%, overhead line, atmospheric temperature 35 degree c.

0 Answers   Bay Fishing Corporation,

How we can change the direction of rotation of Induction motor? Prove it using graphical methods.

4 Answers   Adama University,

What is Difference Between static & Dynamic Pressure of Fan & Blowers

2 Answers  

mention hazard experienced during installation

0 Answers  

why capacitance effect is predominant in underground cable transmission and inductance effect is predominant in over head line transmission?

0 Answers  

which surface is suitable for NEUTRAL GROUNDING ?

1 Answers   NTPC,

The SFC of an engine is 0.25 kg/kW hr. when the fuel used has a calorific value of 36000 kJ/kg. the thermal efficiency of the engine is

0 Answers   Caterpillar,

Why Neutral Busbar CT & transformer neutral CT connected with phase CT in Restricted Earth Fault?

3 Answers