i have sine wave.And i am modulating it at 40khz carrier frequence.is it meant that at one complete cycle of sinusoidal, there would be 38,000 cycles.am i right if now help me plzz

 

No.
Your carrier frequency is 40kHz. You modulate the carrier frequency.
In effect, you are multiplying the modulating signal with the carrier signal.
The modulating signal frequency is generally lower than the carrier frequency.

 

mention the type of modulation.
for example let us consider AM,
if you want to modulate your speech signal using AM,consider a sinusoidal carrier same as that of your example 40khz,then this carrier signal amplitude is varied in accordance with the amplitude of your speech signal,irrespective of your speech signal frequency as we are considered only to transmit speech amplitudes at different instants of time.