A crystal demonstrates the ________ effect when a mechanical force across the cr

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Question
A crystal demonstrates the ________ effect when a mechanical force across the crystal causes a small voltage to be generated.
Options
A. photoelectric
B. Co-pitts
C. piezoelectric
D. flywheel

Correct Answer

piezoelectric

Multivibrators and 555 Timer problems

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2. To obtain a 50% duty cycle in an astable 555 timer circuit:
Options
A. t_LO = t_HI
B. R_A = R_B and short R_B with a diode during the capacitor charging cycle
C. capacitor voltage must rise above 1/3 V_CC
D. t_LO = t_HI, R_A = R_B, and short R_B with a diode during the capacitor charging cycle

4. In a typical IC monostable multivibrator circuit, at the falling edge of the trigger input, the output switches HIGH for a period of time determined by the ________.
Options
A. value of the RC timing components
B. amplitude of the input trigger
C. frequency of the input trigger
D. magnitude of the dc supply voltage

5. If V_cc of a 555 timer circuit is set to +10 V what is the level of output voltage from the circuit?
Options
A. V_OH = 10 V, V_OL = 0 V
B. V_OH = 10 V, V_OL = 0.1 V
C. V_OH = 8.5 V, V_OL = 0 V
D. V_OH = 8.5 V, V_OL = 0.1 V

7. Determine t_HI and t_LO for the circuit given below.
Options
A. t_HI = 7.95 µs, t_LO = 6.24 µs
B. t_HI = 6.24 µs, t_LO = 7.95 µs
C. t_HI = 3.97 µs, t_LO = 3.21 µs
D. t_HI = 3.21 µs, t_LO = 3.97 µs

10. What is the difference between an astable multivibrator and a monostable multivibrator?
Options
A. The astable is free running.
B. The astable needs to be clocked.
C. The monostable is free running.
D. none of the above

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