Question

a metallic wire of length (l)and resistance 5 ohm is stretched to double its length.find its new resistivity and new resistance.assume that there is no change in the density on stretching

Answer 1

resistivity doesn't depend on length of wire

so resistivity has no change

and the new resistance we get with the formula

GIVEN THAT,

R1 = 5ohm

L2 = 2L1



R1/R2 = (L1/L2)²



5/R2 = (L1/2L2)²


5/R2 = (1/2)²


R2 = 5× (2/1)²


R2 = 5× 4


R2 = 20




OKAY IS IT CLEAR

PLEASE MARK AS BRAINLIEST ANSWER IF YOU'VE SATISFIED

Answer 2

Answer:

82 g approx

Method:

no of moles of sulfuric acid = given mass of sulfuric acid/ molar mass of sulfuric acid

ie, no of moles of sulfuric acid = 250 / 98

                                                  = 2.56 moles

now, one mole of sulfuric acid contains 1 moles of Sulfur.

therefore, 2.56 mole of sulfuric acid will contain x moles

x=\frac{1*2.56}{1}x=11∗2.56

= 2.56 mole

Now mass of sulfur = no of moles * molar mass

                                = 2.56 * 32

                                =81.92

                                = 82 g approx