MCQOPTIONS
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MCQOPTIONS
| 1. |
A 200 W sodium street lamp emits yellow light of wavelength \[0.6\,\mu m\]. Assuming it to be 25% efficient in converting electrical energy to light, the number of photons of yellow light it emits per second is |
| A. | \[1.5\times {{10}^{20}}\] |
| B. | \[6\times {{10}^{18}}\] |
| C. | \[62\times {{10}^{20}}\] |
| D. | \[3\times {{10}^{19}}\] |
| Answer» B. \[6\times {{10}^{18}}\] | |