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QAIPMT-2010-Ph-2047: NEET 2010 Physics - Class 11 AIPMT-2010-Ph-2047 Solution: The total radiant energy per unit area normal to the direction…
The total radiant energy per unit area normal to the direction of incidence received at a distance R from the centre of a star of radius r whose outer surface radiates as a black body at a temperature TK is given by
Multiple Choice Options
- A 510 Hz
- B 514 Hz
- C 516 Hz
- D 508 Hz
Step-by-Step Verified Solution
Let the frequencies of tuning fork and piano string be _ 1 and _ 2 respectively.
_ _ 2 = _ 1 � 4 = 512 H z � 4
= 516 Hz or 508 Hz
Increase in the tension of a piano string increases its frequency.
If _ 2 = 516 Hz, further increase in _ 2 , resulted in an increase in the beat frequency. But this is not given in the question.
If _ 2 = 508 Hz, further increase in _ 2 resulted in decrease in the beat frequency. This is given in the question. When the beat frequency decreases to 2 beats per second. Therefore, the frequency of the piano string before increasing the tension was 508 Hz.