Question

ii) With the help of the given diagram, find the following

(a) What is the current through 5ohm resistance ?

(b) What is the current through R ?

(c) What is the value of R ?

(d) What is the value of V ?
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Answer 1

Given:

A circuit diagram

To Find:

(a) The current through 5Ω resistance  

(b) The current through R

(c) The value of R  

(d) The value of V

Solution:

We know that,

• According to Ohm's law, under certain conditions, for a conductor

$\pink{\underline{\boxed{\bf{V=IR}}}}$

where,

V is potential difference

I is current

R is resistance

• In series connection, current through each resistance is same.

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a)

Let the current through 5Ω resistance be I

So,

$\longrightarrow\rm{V=IR}$

$\longrightarrow\rm{10=I(5)}$

$\longrightarrow\rm{5I=10}$

$\longrightarrow\rm{I=\dfrac{10}{5}}$

$\longrightarrow\rm\green{I=2\ A}$

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b)

Since, resistance R and 5Ω resistance are in series connection.

So, current through R is 2 A

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c)

On using ohm's law, we get

$\longrightarrow\rm{V=IR}$

$\longrightarrow\rm{6=2R}$

$\longrightarrow\rm{2R=6}$

$\longrightarrow\rm{R=\dfrac{6}{2}}$

$\longrightarrow\rm\green{R=3\ \Omega}$

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d)

Let the equivalent resistance of circuit be R'

So,

$\longrightarrow\rm{R'=5+3}$

$\longrightarrow\rm{R'=8\ \Omega}$

Here,

Current flowing through circuit is 2 A and equivalent resistance of circuit is 8Ω.

So, on applying Ohm's law, we get

$\longrightarrow\rm{V=2\times8}$

$\longrightarrow\rm\green{V=16\ V}$