The small-signal resistance (i.e., dV_{B}/dI_{D}) in k $\Omega $ offered by the n-channel MOSFET M shown in the figure below, at a bias point of V_{B} = 2 V is (device data for M: device transconductance parameter k_{N} = ${\mu}_{n}{C}_{\mathrm{o}x}^{\text{'}}(W/L)=40\mu A{V}^{2}$, threshold voltage V_{TN} = 1 V, and neglect body effect and channel length modulation effects)
The current i_{b} through the base of a silicon npn transistor is 1+0.1 cos(10000$\pi t$) mA. At 300 K, the r_{$\pi $} in the small signal model of the transistor is
The voltage gain ${A}_{V}$ of the circuit shown below is
In the circuit shown below, capacitors C_{1} and C_{2} are very large and are shorts at the input frequency. v_{i} is a small signal input. The gain magnitude |v_{o}/v_{i}| at 10Mrad/s is
For the BJT Q_{1} in the circuit shown below, $\beta =\infty ,$ V_{BEon} = 0.7v, V_{CEsat}=0.7v, The switch is initially closed. At time t = 0, the switch is opened. The time t at which Q_{1} leaves the active region is
In the silicon BJT circuit shown below, assume that the emitter area of transistor Q1 is half that of transistor Q2.
The value of current I_{0} is approximately
The amplifier circuit shown below uses a silicon transistor. The capacitors C_{c} and C_{E} can be assumed to be short at signal frequency and the effect of output resistance r_{0} can be ignored. If C_{E} is disconnected from the circuit, which one of the following statements is TRUE?
Consider the common emitter amplifier shown below with the following circuit parameters: β=100, g_{m}=0.3861 A/V, r_{0}=∞, r_{x}=259 Ω, R_{S}=1KΩ, R_{B}=93KΩ, R_{C}=250Ω, R_{L}=1kΩ , C_{1}=∞ and C_{2}=4.7μF.
The resistance seen by the source V_{s} is
The lower cut-off frequency due to C_{2} is
A small signal source ${v}_{i}\left(t\right)=A\mathrm{cos}20t+B\mathrm{sin}{10}^{6}t$ is applied to a transistor amplifier as shown below. The transistor has β = 150 and h_{ie} = 3kΩ. Which expression best approximates v_{o}(t)
In the following transistor circuit V_{BE} = 0.7V, r_{e} = 25mV / I_{E}, and $\beta $ and all the capacitances are very large
The value of DC current I_{E} is
The mid-band voltage gain of the amplifier is approximately
The DC current gain ($\beta $) of a BJT is 50. Assuming that the emitter injection efficiency is 0.995, the base transport factor is
For the BJT circuit shown, assume that the $\beta $ of the transistor is very large and V_{BE} = 0.7V. The mode of operation of the BJT is