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Subjects
Science CBSE
Class 9
Sound
Textbook based HOTS
24.
Multiple choice question XXIV
Exercise condition:
2
m.
1
.
For hearing an echo the minimum distance should be:
less than \(10\ m\)
between \(10\ m\) and \(15\ m\)
\(17\ m\) or more
none of the above
2
.
An echo is heard only, if the original sound after reflection should reach the ear in:
less than \(\frac{1}{100}\ s\)
less than \(\frac{1}{10}\ s\)
more than \(\frac{1}{10}\ s\)
none of the above
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