Question

help me in 6th question​

Answer 1

yᴏᴜ ʜᴀᴠᴇ ᴛᴏ ᴜꜱᴇ ᴛʜᴇ ꜰᴏʀᴍᴜʟᴀꜱ ᴡʜɪᴄʜ ᴀʀᴇ ɢɪᴠᴇɴ ʙy ᴍᴇ

ᴩ=ʀ x ᴀ

ʟ

Answer 2

Hiii.....friends,

The answer is here,

Diameter = 0.5mm

So, Radius = 0.25mm = 0.25× 10^-3 m

Resistivity = 1.6 ×10^-8.

Resistance = 10.

We know ,

Resistance(R) = resistivity × length/Area.

$= > \: 10 = \frac{1.6 \times {10}^{ - 8} \times l}{\pi( {0.25 \times {10}^{ - 3)} }^{2} }$

$= > \: l = \frac{625\pi}{16}$

Now if diameter doubles,

=> Diameter = 1mm

So, Radius = 0.5mm

Now, Resistance will be,

$= > \: r = \frac{1.6 \times { 10}^{ - 8} \times 625\pi}{16 \times\pi( {0.5 \times {10}^{ - 3} )}^{2} }$

=> R = 2.5Ohms .

Hence the resistance by 1/4 th times t he initial resistance.

:-)Hope it helps u.