Correct Answer - Option 2 : A bulb with 220 V supply and resistance of 50 ohm
CONCEPT:
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Resistance: The opposition of the flow of current in an electrical circuit is called its resistance.
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Ohm's Law: A law that states that electric current is proportional to voltage and inversely proportional to resistance.
- Mathematically it is written as,
⇒ V = IR or I = V/R
where R is the resistance, I is current, and V is the voltage across the conductor.
Power in resistance:
\(⇒ P=VI = {V^2\over R}=I^2R\)
where I is the current and V is the voltage.
EXPLANATION:
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Option 1: V = 220 volt and R = 100 Ω
\(⇒ P_1= {V^2\over R}= {220^2\over 100}=484 watt\)
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Option 2: V = 220 volt and R = 50 Ω
\(⇒ P_2= {V^2\over R}= {220^2\over 50}=968 watt\)
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Option 3: V = 110 volt and R = 100 Ω
\(⇒ P_3= {V^2\over R}= {110^2\over 100}=121 watt\)
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Option 4: V = 110 volt and R = 50 Ω
\(⇒ P_4= {V^2\over R}= {110^2\over 50}=242 watt\)
- Clearly, the power of the bulb in option 2 is greater than the other.
- We know that If the power of the bulb increases, the bulb will become brighter than before.
- So the bulb in option 2 will glow more brightly than the others. Therefore, the correct answer is option 2.
