If a 4 ohms resistance wire is doubled, determine its new resistance.

Resistance can be depicted as the ratio between the applied voltage to the current flowing through a circuit. The S.I. unit of resistance is Ohms (Ω). 

Determine the Given Data

Initial resistance on the wire, Ri = 4 Ω

Assuming that the initial length of the wire = Li.

As per the given equation, the final length of the wire Lf =2Li

Consider area of the wire = A.

Consider the resistivity of the wire = ρ.

Consider final resistance of the wire = Rf.

Formula Used

We know that resistance is given as,

⇒ \(R = \rho{{L} \over A}\)

⇒ \(\rho= {{RA} \over L}\)

Calculation of New Resistance

Since the resistivity of the wire remains the same in both, we can mention:

\(\rho = {{R_i A} \over L_i} = {{R_fA} \over L_f}\)

⇒ \({{R_i} \over L_i} = {{R_f} \over L_f}\)

Upon value substitution, we can get,

\({{4} \over Li} = {{R_f} \over 2L_i}\)

⇒ R= 8 \(\Omega\)

Therefore, the new resistance is 8\(\Omega\).


Related Questions

  1. What is the necessary condition for a conductor to obey Ohm's Law?
  2. State Ohms law. How can it be verified experimentally?
  3. What are the 3 forms of Ohm's law
  4. What Is Ohm's Law Graph?
  5. How Do You Determine The Resistance Of A Resistor?
  6. Why is the series arrangement not used for domestic circuits?
  7. Why is the curve representing Ohm's law linear?
  8. The resistance R= V/I, where V=100 ± 5.0V and I = 10 ± 0.2A. What is the total error in R?
  9. Find the current through a resistance 2 ohm if the voltage across the resistance is 6V.
  10. What are the applications of ohm's law used in daily life?
  11. Is resistance constant in Ohm's law?
  12. Draw a circuit diagram to verify ohm’s law.
  13. How do you find the resistance in Ohm's law?
  14. What are the limitations of Ohm's Law?
  15. State Ohms Law. Express It Mathematically. Define Si Unit Of Resistance.

Also Check:

CBSE CLASS XII Related Questions

  • 1.
    Four independent waves are expressed as \[ (i)\; y_1=A_1\sin\omega t, \] \[ (ii)\; y_2=A_2\sin 2\omega t, \] \[ (iii)\; y_3=A_3\cos\omega t, \] \[ (iv)\; y_4=A_4\sin\left(\omega t+\frac{\pi}{3}\right) \] The interference between two of these waves is possible in

      • (i) and (iii) only
      • (iii) and (iv) only
      • (i), (iii) and (iv) only
      • All of them

    • 2.
      The figure shows three point charges kept at the vertices of triangle ABC. The net electric field, due to this system of charges, at the midpoint M of base BC will be:

        • \( \frac{q}{4 \pi \epsilon_0 l^2} \) pointing along MA
        • \( \frac{q}{\pi \epsilon_0 l^2} \) pointing along AM
        • \( \frac{q}{2 \pi \epsilon_0 l^2} \) pointing along AM
        • Zero

      • 3.
        Photoemission of electrons occurs from a metal (\( \phi_0 = 1.96 \, \text{eV} \)) when light of frequency \( 6.4 \times 10^{14} \, \text{Hz} \) is incident on it. Calculate: Energy of a photon in the incident light, The maximum kinetic energy of the emitted electrons, and The stopping potential.


          • 4.
            Write any two features of nuclear forces.


              • 5.
                What is displacement current (\( i_d \))? Considering the case of charging of a capacitor, show that \( i_d = \varepsilon_0 \frac{d\Phi_E}{dt} \). What is the value of \( i_d \) for a conductor across which a constant voltage is applied?


                  • 6.
                    Draw a circuit diagram of a full-wave rectifier using p-n junction diodes. Explain its working and show the input-output waveforms.

                      CBSE CLASS XII Previous Year Papers

                      Comments


                      No Comments To Show