I need help with this
In physics, Ohm's law says that current through a wire, I, is directly proportional to voltage, V, and inversely proportional to resistance, R:
I = V/R
It's also true that resistance is directly proportional to the length of the wire. We have a piece of wire. We pass 60 volts through this wire and measure 200 milliamps of current. If I cut the wire in half and pass 400 volts through it, how many milliamps of current will I measure?
How many milliamps of current will I measure?
Hello Guest!
\(I=\dfrac{U}{R}\quad R=\dfrac{U}{I}\\ U=60V\quad I=200mA\\ R=\dfrac{U}{I}=\dfrac{60V}{200mA}\cdot \dfrac{1000mA}{A}\\ R=300\Omega\\ \quad\\ I=\dfrac{U}{R}\\ U=400V\quad R=\dfrac{300\Omega}{2}=150\Omega\)
\(I=\dfrac{400V}{150\Omega}\cdot \dfrac{1000mA}{A}\\ \color{blue}I=2667mA\)
2667 milliamps of current will I measure.
!