1. An RC coupled amplifier has an open loop gain of 200 and a lower cutoff frequency of 50 Hz. If negative feedback with β = 0.1 is used, the lower cut off frequency will be
2. In figure v1 = 8 V and v2 = 4 V. Which diode will conduct?
3. The load impedance ZL of a CE amplifier has R and L in series. The phase difference between output and input will be
4. This is the first time that I ......... her song.?
5. If an amplifier with gain of - 1000 and feedback factor β = - 0.1 had a gain change of 20% due to temperature, the change in gain of the feedback amplifier would be
6. In figure The minimum and maximum load currents are
7. In figure, VEB = 0.6 V, β = 99. Then VC and IC are
8. The input impedance of op-amp circuit of figure is
9. In a BJT circuit a pnp transistor is replaced by npn transistor. To analyse the new circuit
10. To protect the diodes in a rectifier and capacitor input filter circuit it is necessary to use
11. The output V0 in figure is
12. In a CE amplifier the input impedance is equal to the ratio of
13. For a system to work, as oscillator the total phase shift of the loop gain must be equal to
14. An amplifier has a large ac input signal. The clipping occurs on both the peaks. The output voltage will be nearly a
15. The transistor of following figure in Si diode with a base current of 40 μA and ICBO = 0, if VBB = 6V, RE = 2 kΩ and β = 90, IBQ = 20 μA then RB =
16. In the amplifier circuit of figure hfe = 100 and hie = 1000 Ω. The voltage gain of amplifier is about
17. The efficiency of a full wave rectifier using centre tapped transformer is twice that in full wave bridge rectifier.
18. Assertion (A): CE amplifier is the most widely used BJT amplifierReason (R): CE amplifier has zero phase difference between input and output
19. Assertion (A): For large signal variations an amplifier circuit has to be analysed graphicallyReason (R): The output characteristics of a transistor is nonlinear.
20. Negative feedback reduces noise originating at the amplifier input.
21. Maximum efficiency of class B power amplifier is 50%.
22. In figure what is the base current if VBE = 0.7 V
23. In figure ID = 4 mA. Then VS =
24. The self bias provides
25. In figure what is value of IC if βdc = 100. Neglect VBE