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Two black spheres radiate the same power (or powers in a given ratio): ratio of their radii

The same question, asked 5 times: 3 May 2023 S1, 11 May 2024 S1*, 23 Apr 2025 S1, 26 Apr 2025 S2*, 18 Apr 2026 S1. Every wording below, oldest first.

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  1. Question 1

    3 May 2023 S1

    48
    Two spherical black bodies of radii 'R1R_1' and 'R2R_2' and temperatures 'T1T_1' and 'T2T_2' radiate the same power. The ratio 'R1R_1' to 'R2R_2' will be

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  2. Question 2

    11 May 2024 S1

    3
    Two spherical black bodies of radii r1r_1 and r2r_2 at temperature T1T_1 and T2T_2 respectively radiate power in the ratio 1:21:2. Then r1:r2r_1 : r_2 is

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  3. Question 3

    23 Apr 2025 S1

    49
    Two spherical black bodies have radii ' R1R_{1} ' and ' R2R_{2} '. Their surface temperatures are T1 KT_{1}\text{ }K and T2 KT_{2}\text{ }K respectively. If they radiate the same power, the ratio R1R2\frac{R_{1}}{R_{2}} is

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  4. Question 4

    26 Apr 2025 S2

    5
    Two spherical black bodies have radii ' R1R_{1} ' and ' R2R_{2} '. Their surface temperatures are ' T1T_{1} ' and ' T2T_{2} '. If they radiate same power, then R2R1\frac{R_{2}}{R_{1}} is

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  5. Question 5

    18 Apr 2026 S1

    113
    Two spherical black bodies of radii R1R_1 and R2R_2 having surface temperature T1T_1 and T2T_2 respectively, radiate the same power. The ratio of R1R_1 to R2R_2 will be

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