Objective
To find the maximum permissible cable resistance require for the load to still function normally.
Procedure
Turn Power supply to 12V
Measure the true value of the power supply
Adjust the resistor box in order to make the voltage of the load be as close to 11V
The resistance we found was 105 Ohm
Resistor box power rating: 1 W
Max power supply voltage: 12V (Actual: 12.28)
Voltage of the load: 11.0V
Current in the circuit: 11.3 mA
Resistor box reading: 105 ohm
Question
#a
I*t=0.8
t=0.8/I=0.8/11.3*10^-3
=70.8 hr
#b
Power to the load=V^2/R=11^2/1000
=0.121 W
Power to the Cable=I^2R=(11.3*10^-3)^2*105
=0.0134 W
Power efficiency=0.121/(0.121+0.0134) *100%
=90.02%
#c
No, the power capability of the resistor box is 1W which is greater than 0.0134W
#d
105/0.3451=304.3m
The maximum distance between the battery and the load=304.3/2
=152.15m
#e
5.0V-2.6V=20mA*R
R=2.4/20mA=120 ohm
L=120/0.2129=563.6m
distance =L/2=281.8m
#f
48V=36V+IR
R=1.2 ohm
Resistivity=1.2/60=0.02ohm/ft
#e
5.0V-2.6V=20mA*R
R=2.4/20mA=120 ohm
L=120/0.2129=563.6m
distance =L/2=281.8m
#f
48V=36V+IR
R=1.2 ohm
Resistivity=1.2/60=0.02ohm/ft
