Three discs A, B and C having radii $$2m$$, $$4m$$, and $$6$$ m respectively are coated with carbon black on their other surfaces. The wavelengths corresponding to maximum intensity are $$300$$ nm, $$400$$ nm and $$500$$ nm, respectively. The power radiated by them are Qa, Qb and Qc respectively

Question

Three discs A, B and C having radii $$2m$$, $$4m$$, and $$6$$ m respectively are coated with carbon black on their other surfaces. The wavelengths corresponding to maximum intensity are $$300$$ nm, $$400$$ nm and $$500$$ nm, respectively. The power radiated by them are Qa, Qb and Qc respectively

Infinity Learn · Accepted Answer

Radiated power P $$=$$ A∈σ$$T4$$  ⇒ P ∝ $$AT4From$$ Weins's law,  λmT $$=$$ constant ⇒ T ∝ $$1$$λm∴  P   ∝ $$A($$λ$$m)4$$∝$$r2($$λ$$m)4$$⇒ Qa:Qb:Qc $$=$$ $$22(300)4$$:$$42(400)4$$:$$62(500)4$$ ∴ Qb will be maximum

Three discs A, B and C having radii 2m, 4m, and 6 m respectively are coated with carbon black on their other surfaces. The wavelengths corresponding to maximum intensity are 300 nm, 400 nm and 500 nm, respectively. The power radiated by them are $Q_{a}, Q_{b} and Q_{c}$ respectively

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Three discs A, B and C having radii 2m, 4m, and 6 m respectively are coated with carbon black on their other surfaces. The wavelengths corresponding to maximum intensity are 300 nm, 400 nm and 500 nm, respectively. The power radiated by them are Qa, Qb and Qc respectively

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Ready to Test Your Skills?

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Three discs A, B and C having radii 2m, 4m, and 6 m respectively are coated with carbon black on their other surfaces. The wavelengths corresponding to maximum intensity are 300 nm, 400 nm and 500 nm, respectively. The power radiated by them are $Q_{a}, Q_{b} and Q_{c}$ respectively