A) \[60:1\]
B) \[72:1\]
C) \[720:1\]
D) \[3600:1\]
Correct Answer: C
Solution :
: The second-hand completes one rotation in 1 min and the hour-hand completes in 12 h. \[\therefore \] The angular speed of the second-hand is \[{{\omega }_{s}}=\frac{2\pi \,rad}{1\min }=\frac{2\pi \,rad}{60s}\] and that of the hour-hand is \[{{\omega }_{s}}=\frac{2\pi \,rad}{12h}=\frac{2\pi \,rad}{12\times 60\times 60s}\] Their corresponding ratio is \[\frac{{{\omega }_{s}}}{{{\omega }_{h}}}=\frac{\frac{2\pi \,rad}{60s}}{\frac{2\pi \,rad}{12\times 60\times 60s}}=\frac{12\times 60\times 60}{60}=\frac{720}{1}\]
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