54501. In calculating input impedance, the load impedance is considered to be connected at the output.
54502. In a transistor βdc is likely to vary between 100 and 400. The proper value of βdc to be used to located Q point is
54503. Which of the following noise becomes of great importance at high frequencies?
54504. Assertion (A): The duty cycle of a class C amplifier affects the power dissipation of transistorReason (R): At higher harmonics the efficiency of a class C amplifier becomes poor
54505. If the op-amp in figure has a unity gain frequency of 1 MHz, the cut off frequency is
54506. In a self bias circuit for CE amplifier the collector supply voltage is made twice. The collector current will
54507. In a full wave voltage doubler circuit, the input frequency is 560 Hz. The ripple frequency is
54508. Assertion (A): A tuned amplifier uses a parallel tuned circuitReason (R): A tuned amplifier is used to amplify a narrowband frequencies
54509. The ac collector current is nearly equal to
54510. From a measurement of the rise time of the output pulse of an amplifier whose input is a small amplitude square wave, one can estimate the following parameter of the amplifier
54511. In an amplifier, if the output current flows for 120° of the input cycle, the class of amplifier will be
54512. Assertion (A): If we overdrive an amplifier the output signal may get clippedReason (R): To dissipate heat to atmosphere a heat sink is sometimes attached to the case of transistor
54513. Which op-amp circuit uses a diode as one of the circuit components?
54514. Overall efficiency of class B amplifier is
54515. For a transistor to have-a larger β it must have and a
54516. JFET is also known as
54517. Drain feedback bias is often used with
54518. CMRR of a difference amplifier is equal to
54519. In a class C amplifier, full cycle conductor of the current is achieved by employing
54520. Higher order active filters are used for variable
54521. Which of the following statement is false?
54522. Assertion (A): The main use of Miller integrator is to generate rampReason (R): An inverting amplifier can handle more than one input at the same time.
54523. In figure, IC ≈
54524. High cut off frequency can be expected in case of
54525. Which coupling produces the minimum interference with frequency response?
54526. Assertion (A): A sine wave with slew rate distortion looks rectangularReason (R): The maximum rate of output voltage change is called slew rate
54527. In a P-N-P transistor, electrons flow
54528. A generator with an internal resistance of 600 Ω drives an amplifier whose input resistance is 400 Ω. The generator's open circuit voltages is 1 mV; the amplifier develops 100mV across an 8kΩ load. The input voltage to the amplifier is
54529. Thermal run away of a transistor occurs when
54530. JFET has __________ degree of isolation between input and output, and a __________ noise figure.
54531. The advantage of FET over BJT is
54532. The MOSFET is almost ideal as a switching device because
54533. The input and output signals for CE amplifier are always
54534. The voltage gains of an amplifier without feedback and with negative feedback respectively are 100 and 20. The percentage of negative feedback (β) would be
54535. Figure shows a
54536. Three cascaded stages have gains of 10, 20 and 25. The overall gain will be
54537. Find the odd one out
54538. The equivalent circuit shown in figure is for
54539. In a one pole active low pass filter, the cut off frequency is fc. Then
54540. Turn off time of a transistor switch is equal to (where ts is storage time and tf is fall time.)
54541. In a CE amplifier circuit the emitter by pass capacitor is remove. The ac output voltage
54542. In a differential amplifier, CMRR can be improved by using an increased
54543. If ac resistance of diode is re, then In CE, BJT amplifier the input impedance is
54544. Pick the odd-one out
54545. In a CE amplifier the output coupling capacitor is short circuited. The dc collector voltage
54546. A certain transistor has a dc of 0.98 and a collectors leakage current of 5 μA. If IE = 1 mA, the collector current will be
54547. If 1.5% of the output of an amplifier is feedback positively to the input, the minimum gain required of the amplifier for oscillations to occur, is
54548. The use of a capacitor filter in a rectifier circuit gives satisfactory performance only when the load
54549. The transconductance curve of a JFET is
54550. The input resistance R, of an ideal voltage amplifier is __________ and that of a current amplifier is __________ .