Question

*What is the total equivalent resistance of the circuit?
*What would be the reading of the ammeter?
* What would be the reading of a voltmeter connected between the points Q and R?
*What would be the reading of the ammeter if only the highest of the three resistors (= 50) were present alone in the circuit?
*What would be the reading of a voltmeter connected between the points P and S.​

Answer 1

Explanation:

Labelling each of the resistance as shown in the figure below.

Resistance R

1

and R

2

are in series

⇒ R

s1

=R

1

+R

2

⇒ R

s1

=3+3=6 Ω

Now R

s1

and R

3

are in parallel.

⇒

R

p

1

=

R

s1

1

+

R

3

1

⇒

R

p

1

=

6

1

+

3

1

⇒

R

p

1

=

6

1+2

=

6

3

⇒R

p

=

3

6

=2

⇒R

p

=2 Ω

Now R

4

,R

p

and R

5

are in series.

⇒R

eq

=R

4

+R

5

+R

p

⇒R

eq

=0.5+2+0.5=3 Ω

Hence the Equivalent resistance of the circuit is 3 Ω.

For Ammeter Reading

Current (I)=

R

V

=

3

3

=1A

Hence the current reading in ammeter is 1 A