Answer Posted / guest
u know every metal oxidises by giving its valence
electron.so metal corrode with time.metal corrodes due to
environmental effects like moisture etc.suppose u r giving
+48 then metal will loose its electron quickly & will be
oxidised. So the metal will be corroded quckly & u have to
replace it .But if u give -48 then metal will not loose its
electrons because the metal wire will be negatively
charged.if metal somehow looses its electron then metal can
draw electron from the current becoz the wire is negatively
charged.so metal will not corrode with time.Thats why we
uses -ve supply(-48v).Moreover if we use +ve supply(more
load more corrosion)ie if load is high metal will be corrode
Quickly.in our MSC sites we use load upto 600 amps.in this
case if we will use +ve supply we have to replace the wires
frequently.if we use -ve supply there will be no problem
| Is This Answer Correct ? | 14 Yes | 2 No |
Post New Answer View All Answers
What do you mean by operating point?
Explain the difference between silicon controlled switch (scs) and gate turn-off switch (gto)?
What is a sample and hold circuit? Where it is used?
Tell me why gold is added to the p-n junction?
Why every time that I hit the microphone or when I speak louder the amplifier is switched of?
Give application of wireless modem.
ssr function?
What is an amplifier?
what is BFU ? what is the working of BFU in BTS?
Explain what are the basic logic elements?
How many types of resistor are there in diode?
what FET were we use its
Which is the most commonly used code for representing alphanumeric information?
how to interface hall effect sensor with 8051 microcontroller?
Can you help me correct FM transmitter circuit?