Question

b) Identify the pair of parallel lines in Fig. 4. Give reasons for your answer.
K
G
Α Ε
B
122°
A
D
55°
57°
С
123°
Р
H
F
Fig. 4​

Answer 1

Answer:

Step-by-step explanation:

In the figure given

let voltages at A,B,C,D be V

A

​

,V

B

​

,V

C

​

,V

D

​

.

Let V

A

​

>V

B

​

.

given V

A

​

−V

B

​

=16V

let current from A to B be

′

i

′

(through r1,r4,r5)

let current from C to D through r2 be i

1

​

, then current from r3 will be i−i

1

​

from C to D.

On applying 'Kirchhoff's voltage law' in the closed loop with 9V source :-

9−2(i−i

1

​

)+1i

1

​

=0

⇒i

1

​

=

3

2i−9

​

.....(1)

On applying 'Kirchhoff's voltage law' from A to B:-

V

A

​

−4i−9−1i

1

​

+3−1i−3i−V

B

​

=0

⇒16−8i−6−i

1

​

=0 (∵V

A

​

−V

B

​

=16)

⇒30−26i+9=0(∵ from equation (1))

⇒i=1.5A

⇒i

1

​

=−2A

So current through r1,r4,r5 is 1.5A.

current through r2 is 2A.

current through r3 is 0.5A.

solution

Hope it helps you ✌️