# In resonance column experiment to determine the velocity of sound, $L$ person observes first resonance at $12\;cm$. If she repeats the experiment on a very hot day her resonance column length would be

$(a)\;=12\;cm \\(b)\; > 12 \;cm\\(c)\; < 12\;cm\\(d)\;\text{may be any thing}$

As velocity of sound increases with increase in temperature the balancing length will also increase.
Hence length > 12 cm
Hence b is the correct answer.