Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
BITSAT2023PhysicsCurrent ElectricityActual

The resistance of a wire is 5 . It's new resistance in ohm if stretched to 5 times of its original length will be :

Options

  1. A625
  2. B5
  3. C125
  4. D25

Correct answer

C. 125

Step-by-step solution

Let resistance of a wire R and length 1 . R = A =5 Volume of wire is constant in stretching V_i=V_f A_i _i=A_f _f A = A ^ (5 ) A ^ = A 5 R_f= _f A_f = (5 ) ( A 5 ) =25 ( A )=25 5=125

Practice Current Electricity on Quantrex Academy →

More from Current Electricity

In the given circuit, E₁=E₂=E₃=2 ~V and R₁=R₂=4 , then current flowing through the branch A B is 2024In the following circuit diagram, when 3 resistor is removed, then equivalent resistance of the network 2024A conducting wire is stretched by applying a deforming force, so that its diameter decreases to 40 % of original value. The percentage change in its resistance will be 2024A wire of resistance 160 is melted and drawn in wire of one-fourth of its length. The new resistance of the wire will be 2024Five cells each of emf E and internal resistance r send the same amount of current through an external resistance R whether the cells are connected in parallel or in series. Then t 2024Ratio of thermal energy released in two resistor R and 3 R connected in parallel in an electric circuit is : 2023In the arrangement shown in figure, when the switch S₂ is open, the galvanometer, shows no deflection for l=50 ~cm when the switch S₂ is closed, the galvanometer shows no deflectio 2022An electric current I enters and leaves a uniform circular wire of radius r through diametrically opposite points. A charged particle q moves along the axis of circular wire passes 2022 Full Current Electricity list All BITSAT PYQs