A small bulb has a resistance of 2 ohm when it is cold. It draws 0.4 ampere current from a source of 4 V and then starts glowing. Calculate the resistance when it is glowing.

Given: Resistance (R cold) = 2 Ohm

Current (I) = 0.4 Ampere

Voltage (V) = 4 V

The resistance when the bulb is glowing is calculated by using Ohm’s law.

According to Ohm’s law,

V = I x R

Substituting the values in the above equation, we get

R = 4/0.4

R = 10 Ohm


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  4. What Is Effective Resistance?
  5. Why is the curve representing Ohm's law linear?
  6. State And Explain Joules Law Of Heating.
  7. State Ohms law. How can it be verified experimentally?
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  9. State Ohms Law. Express It Mathematically. Define Si Unit Of Resistance.
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  11. What Is The Basic Principle Of Ohm's Law?
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  13. Why Do We Use Ohm's Law?
  14. What are the applications of ohm's law used in daily life?
  15. 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 as all three appliances, and what is the current through it?

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