Voltage in circuit

Question

Answer 1

(1)

Step 1:

Observe the circuit.

The resistance and are connected in parallel.

Equivalent resistance : .

Parallel equivalent resistance : .

Step 2:

The resistance and are connected in parallel.

Equivalent resistance : .

Parallel equivalent resistance : .

Step 3:

Redraw the circuit replacing resistors and .

Now apply source transformation to convert current source in parallel to resistor R to voltage source in series with the resistor R.

Voltage across the resistor is .

Redraw the circuit using source transformation.

Voltage across the parallel network is same, hence .

Since , the voltage across the terminal A and B is .

Solution:

Voltage across the terminal A and B is .

Answer 2

(2)

Step 1:

Observe the circuit.

The resistance  and  are connected in parallel.

Equivalent resistance : .

Parallel equivalent resistance : .

Step 2:

The resistance  and  are connected in parallel.

Equivalent resistance : .

Parallel equivalent resistance : .

Step 3:

Redraw the circuit replacing resistors  and . 

Now apply source transformation to convert source to voltage source.

Voltage across the resistor  is .

Redraw the circuit using source transformation.

All the resistors are connectted in series.

Hence equivalent resistance is .

.

Comments

Contd...

Step 4:

The total resistance of the circuit is .

Find the current flowing in the circuit.

Current flowing in the circuit is .

Current flowing in the circuit is .

Find the voltage across the A and B.

Voltage across A and B is the voltage drop across the  resistor.

Voltage drop across the  resistor : .

Since , the voltage across the terminal A and B is  V.

Solution:

Voltage across the terminal A and B is  V.