Circuits…help please?

3 Answers

• 6ohms x 4A = 24V

  24V/8 ohms = 3A

  4A+3A=7A (current through 25 ohms)

  7Ax25 ohms=175V

  E=175V+24V

  =199V

  199V/20 ohms

  =9.95A (current through 20 ohms)

• Here you need to calculate the voltage across the 6 ohm resistor with V = IR. (24)

  Then you will know the voltage across the 8 ohm resistor is the same. (24)

  From V = IR you then calculate the current through the 8 ohm resistor.(3)

  By adding the current through the 6 ohm and the 8 ohm resistors, you will have the current through the 25 ohm resistor. (7) Then from V = IR, you can calculate the voltage across the 25 ohm resistor.(175)

  Now by adding the voltage across the 6 ohm and the 25 ohm resistors, you have the voltage across the 20 ohm resistor. (199)

  From V = IR, you can figure the current through the 20 ohm resistor. (9.95)

• v through the 6 ohm resistor=I X R=4×6=24V

  v through the 8 ohm resistor=24V

  I through the 8 ohm resistor=24/8=3A

  total current in upper part=3+4=7A

  therefore current through the 25 ohm resistor=7A

  v through the 25 ohm resistor=25 x 7=175V

  total voltage in the upper part=24+175=199V

  therefore the voltage in the lower part=199v

  I in the 20 ohm resistor= V/R=20/199=0.1A