While using a frequency counter for measuring frequency, two modes of measurement are possible: Period time Frequency mode There is a ‘cross-over frequency’ below which the period mode is preferred. Assuming the crystal oscillator frequency to be 4MHz, the crossover frequency is given by

• A.  2 Mhz.
• B.  1Khz.
• C.  8 Mhz.
• D.  2 Khz.

Answer: (A)