Question

A wire is 200 cm long, 0.50m in diameter and has a resistance of 3.0 ohm. Another wire of the same material is 300 cm by 0.60 mm in diameter. What is he total resistance of the two wires when connected in series?

Answer 1

Answer:

isme karna kya hai question

Answer 2

Answer:

$\LARGE{ \underline{ \bf{Required \: answer:}}}$

$\large{ \boxed{ \boxed{ \rm{1.5 \: ohm}}}}$

Explanation:

We have,

Resistance of 1 m wire = 3 Ω

Now, we know that resistance is directly proportional to length and is given by R = Resistivity × Length / Cross-sectional Area. Resistivity and Cross sectional area will remain same, then Resistance will vary with length.

Then,

Resistance of 1.5 m wire = 3 × 1.5 Ω = 4.5 Ω

So, we have three lengths of resistors with resistance 4.5 Ω. They are connected in parallel. Then equivalent resistance:

$\rm{ \dfrac{1}{R_eq.} = \dfrac{1}{R_1} + \dfrac{1}{R_2} + \dfrac{1}{R_3}}$

We have, R1 = R2 = R3. Hence Req. = R/3

$\rm{R_eq. = \dfrac{4.5}{3} } = 1.5 ohm$

And we are done! :D