Question

A circuit is shown in the diagram given below.
(a) Find the value of R.
(b) Find the reading of the ammeter.
(c) Find the potential difference across the terminals of the battery.

Answer 1

(a) Current 'I' through the resistor can

be written as (6V/R)

So,

I = V/R

6V/R = 12V/6

R = 3

(b) Ammeter reading will be same as

current through R.

6V/3 = 2A

(C) Potential difference across the

battery terminals is

6V+12V=18V

Answer 2

Answer:

a)  Resistance( R )= 3Ω

b) Ammeter shows reading  2A

c) Potential drop across battery terminals is 18 volt.

Explanation:

Given R and 6 Ω will be V₁=6 v and V₂=12 v respectively. As voltage is the same across parallel combinations.

so total voltage across the circuit

V =  V₁ + V₂

V = 6 + 12

V = 18 v

now Because the current in a series combination is the same, the current through a 6-ohm resistor will be the same

  I= V/R

  I= 12 /6

  I = 2 Ampere

Resistance on resistor R

R= V/I

R= 6/2

R = 3 Ω

Hence resistance = 3 ohm ,

           ammeter reading =2ampere,

           potential =18v.