If a 1 $\mathrm { M } \Omega$ resistor, 0.47 $\mathrm { M } \Omega$ resistor and 0.5 $\mathrm { M } \Omega$ resistor are connected in parallel across an 18 V source, what is the total current if the 1 $\mathrm { M } \Omega$ resistor opens?
A) 74.3 $\mu A$
B) 74.3 mA
C) 92.3 mA
D) 92.3 $\mu A$

Question

If a 1 $\mathrm { M } \Omega$ resistor,  0.47  $\mathrm { M } \Omega$ resistor and  0.5  $\mathrm { M } \Omega$ resistor are connected in parallel across an  18 V  source, what is the total current if the 1 $\mathrm { M } \Omega$ resistor opens?
A)  74.3  $\mu A$
B)  74.3 mA
C)  92.3 mA
D)  92.3  $\mu A$

Quizplus · Accepted Answer

When the 1 MΩ resistor opens, the circuit becomes a simple parallel circuit with two resistors: 0.47 MΩ and 0.5 MΩ. The total resistance of the circuit is:```1/RT = 1/R1 + 1/R21/RT = 1/0.47 MΩ + 1/0.5 MΩRT = 0.282 MΩ```The total current in the circuit is:```I = V/RTI = 18 V / 0.282 MΩI = 74.3 μA```

If a 1 MΩ\mathrm { M } \OmegaMΩ Resistor, 0 MΩ\mathrm { M } \OmegaMΩ

If a 1 $\mathrm { M } \Omega$ Resistor, 0 $\mathrm { M } \Omega$