An electric lamp of 100 Ohms, a toaster of resistance 50 Ohms, and a water filter of resistance 500 Ohms are connected in parallel to a 220 V source. What is the resistance of an electric iron connected to the same source that takes as much current?

Given parameters:

  • Resistance of electric lamp (R1) = 100 Ω
  • Resistance of toaster (R2) = 50 Ω
  • Resistance of water filter (R3) = 500 Ω
  • A potential difference of the source (V) = 220 V

To find:

  • The flow of electric current through the electric iron.
  • Resistance of an electric iron

The three resistors are connected in parallel as shown – 

All 3 resistances are connected in parallel

Solution:
1) The total resistance (R) can be calculated by – 

1/R = 1/R1 + 1/R2 + 1/R3

1/R = 1/100  + 1/50 + 1/500

1/R = (5 + 10 + 1)/500

1/R = 16/500

Total Resistance (R) = 500/16 = 31.25 Ω

2) According to Ohm’s law, the current through a conductor is directly proportional to the voltage across two points of a conductor.

V = IR

Where R is constant called resistance.

R = V/I

I = 220 × (16/500)

I = 7.04 A

Therefore, the resistance of the electric iron is 31.25 Ω and the current flowing through it is 7.04 A.


Related Questions

  1. What is the necessary condition for a conductor to obey Ohm's Law?
  2. How do you find the resistance in Ohm's law?
  3. What Is Effective Resistance?
  4. Why is the curve representing Ohm's law linear?
  5. What Is Ohm's Law Graph?
  6. State Ohms law. How can it be verified experimentally?
  7. What are the limitations of Ohm's Law?
  8. What are the 3 forms of Ohm's law
  9. Why Do We Use Ohm's Law?
  10. State Ohms Law. Express It Mathematically. Define Si Unit Of Resistance.
  11. Draw a circuit diagram to verify ohm’s law.
  12. What Is The Basic Principle Of Ohm's Law?
  13. What are the applications of ohm's law used in daily life?
  14. Is resistance constant in Ohm's law?
  15. Obtain the equation J = σE of Ohm's law on the basis of drift velocity

Read More:

CBSE CLASS XII Related Questions

  • 1.
    A light copper ring is freely suspended by a light string. A bar magnet is held horizontally with its length along the axis of the ring. The magnet is moved towards the ring with its N pole facing the loop. What will happen to the ring and its position? Explain.


      • 2.
        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.


          • 3.
            Two parallel plate capacitors X and Y are connected in series to a 6 V battery. They have the same plate area and same plate separation but capacitor X has air between its plates, whereas capacitor Y contains a material of dielectric constant 4. Calculate the capacitances of X and Y, if the equivalent capacitance of the combination of X and Y is \( 4 \, \mu\text{F} \). Calculate the potential difference across the plates of X and Y.


              • 4.
                Assertion (A) : The mass of a nucleus is less than the sum of the masses of the constituent nucleons. Reason (R) : Energy is absorbed when the nucleons are bound together to form a nucleus.

                  • Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
                  • Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
                  • Assertion (A) is true, but Reason (R) is false.
                  • Both Assertion (A) and Reason (R) are false.

                • 5.
                  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

                  • 6.
                    Draw the number of scattered particles versus the scattering angle graph for scattering of alpha particles by a thin foil. Write two important conclusions that can be drawn from this plot.

                      CBSE CLASS XII Previous Year Papers

                      Comments


                      No Comments To Show