- #1
fisico30
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Ohmic loss, ohm's law, resistance etc...
hello, just a simple question about power dissipation in the form of heat.
If a conductor has infinite conductivity (zero resistivity) then the voltage across it is zero, so
by the formula P= I^2 R, it dissipates zero power as heat.
but if I use the formula P=V^2/R, would I get an indeterminate form: 0/0 since V=0 and R=0 ?
In a simple circuit, if the load is meant to generate a lot of heat (for heating or cooking) , do we surely want the wires to be very conducting and dissipate almost no heat (small wire gauge_, but do we want the load resistor to large or small?
IF the voltage is constant, it appears that we would need a small load resistor R_L, according to the first formula so more current goes out ( and current is at the 2nd power)...
If the resistance were too big, little current would go out, and little power dissipated.
It seems that the more the resistance, the less the ohmic loss...
something wrong here..
thanks
hello, just a simple question about power dissipation in the form of heat.
If a conductor has infinite conductivity (zero resistivity) then the voltage across it is zero, so
by the formula P= I^2 R, it dissipates zero power as heat.
but if I use the formula P=V^2/R, would I get an indeterminate form: 0/0 since V=0 and R=0 ?
In a simple circuit, if the load is meant to generate a lot of heat (for heating or cooking) , do we surely want the wires to be very conducting and dissipate almost no heat (small wire gauge_, but do we want the load resistor to large or small?
IF the voltage is constant, it appears that we would need a small load resistor R_L, according to the first formula so more current goes out ( and current is at the 2nd power)...
If the resistance were too big, little current would go out, and little power dissipated.
It seems that the more the resistance, the less the ohmic loss...
something wrong here..
thanks