Thermodynamics — Physics STD 11 Science — Question

Three light sources A, B and C emit equal amount of radiant energy per unit time. The wavelengths emitted by the three sources are 450nm, 555nm and 700nm respectively. The brightness sensed by an eye for thesources are X_A, X_B and X_C respectively. Then, 

1. X_A > X_B, X_C > X_B
2. X_A > X_B, X_B > X_C
3. X_B > X_A, X_B > X_C
4. X_B > X_A, X_C > X_B

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Mark the correct statements:

1. Equations of special relativity are not applicable for small speeds.
2. Equations of special relativity are applicable for all speeds.
3. Nonrelativistic equations give exact result for small speeds.
4. Nonrelativistic equations never give exact result.