badge image

Enroll For Free Now & Improve Your Performance.

×
User Icon
User Icon
User Icon
User Icon
User Icon

Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade: 12th pass

                        

A wire of resistance 10 ohm is stretched 20% determinant its new resistance

8 months ago

Answers : (2)

Arun
24742 Points
							
resistance is given by, R = ρl/A
 
R = ρl²/(Al) = ρl²/V.....(1), where V is volume of wire.
 
at constant volume, V resistance of wire depends on only length of wire.
 
as it is clear in expression (1), resistance is directly proportional to square of its length.
 
now, according to question,
 
length is increased by 20%
 
so, new length of wire = l + 20% of l
 
= l + 0.2l = 1.2l
 
now, new resistance , R' = ρ(1.2l)²/V....(2)
 
from equations (1) and (2),
 
R'/R = 1.44 => R' = 1.44R
 
it is given initial resistance, R = 10ohm
 
so, R' = 1.44R = 14.4ohm
 
 
8 months ago
Vikas TU
12278 Points
							
Dear student 
resistance is given by, R = ρl/A
R = ρl²/(Al) = ρl²/V.....(1), where V is volume of wire.
at constant volume, V resistance of wire depends on only length of wire.
as it is clear in expression (1), resistance is directly proportional to square of its length.
now, according to question,
length is increased by 20%
so, new length of wire = l + 20% of l
= l + 0.2l = 1.2l
now, new resistance , R' = ρ(1.2l)²/V....(2)
from equations (1) and (2),
R'/R = 1.44 => R' = 1.44R
Good Luck 
8 months ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


Course Features

  • 101 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 110 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details