Changing the number of cycles of an sinusoidal input signal Imagine we have an ultrasonic sensor that transmits a multiple cycles of sinusoidal signal/waveform that can travel up to a specific distance/range. 

Can we achieve more distance coverage using more number of cycles in the input signal (at the same frequency) or this change can not affect the coverage?

I understand that more number of cycles will result in more signal energy. Does that mean that having more energy in the signal will result in less signal deterioration when SNR goes down in longer distances due to attenuation?
So yes, increasing the duration of the transmitted sinusoidal pulse (by increasing the number of cycles transmitted) will provide improved detection at the same SNR.

This is equivalent to a brute force bit duplication used to decrease the bit error rate (hence improve the reliable communication) at a given SNR. Note, however, that you will be transmitting at a slower rate than a shorter window. 

So in effect, this method of longer window will compromise transmission rate vs improved detection at longer distance (lower SNR).