Question

At junction P, currents \[0.2\,\mathrm{A}\], \[0.6\,\mathrm{A}\], and \[0.7\,\mathrm{A}\] point towards P, while \[0.4\,\mathrm{A}\], \[0.5\,\mathrm{A}\], and \[I\] point away. What is the unknown current?

Options

• \[0.6\,\mathrm{A}\]

• \[1.5\,\mathrm{A}\]

• \[0.2\,\mathrm{A}\]

• \[0.9\,\mathrm{A}\]

Answer 1

Taking currents towards P as positive gives \[0.2-0.4+0.6-0.5+0.7-I=0\]. This simplifies to \[0.6-I=0\], so \[I=0.6\,\mathrm{A}\].