Problem:

Determine the total resistance of this parallel circuit when:

R1 = 270W
R2 = 180W

 

Procedure:

1. State the appropriate equation:

RT =

R1R2

R1 + R2
 

2. Substitute the given values:

R1R2

= 270 x 180
R1 + R2 270 + 180
 

3. Complete the calculation:

270 x 180 = 108
270 + 180
 
Solution

RT = 108W

 

Problem:
Given

Determine

Procedure:

1. Find the total resistance

RT = R1 + R2
RT= 1k + 2k
 
RT = 3kW
 

2. Calculate the total current

IT = VT= 12 =  4mA
RT3k
 

3. Determine the current for each resistor

IR1 = IR2 = IT = 4mA

An important characteristic of series circuits is that the same amount of current flows through each element of  the circuit, including the source and all resistors.
Solution
IT = 4mA
IR1 = 4mA
IR2 = 4mA
 

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