Refresher Exam - Elec 03
The 'h' parameters of the circuit shown in the figure are h_ib = 25 Ω, h_fb = 0.999 and h_ob = 10¯⁶ Ω. What is the voltage gain?
400
What is the time constant of the circuit in figure shown?
RC/2
What is the rms value of the wave shown in the figure?
about 80 V
All but which one of the following statements regarding extrinsic semiconducting silicon is true?
The number of n-type carriers equals the number of p-type carriers in extrinsic silicon.
To prevent a DC return between source and load, it is necessary to use _______.
capacitor between source and load
If the cross-sectional area of a magnetic field increases, but the flux remains the same, the flux density _______.
decreases
An RLC series circuit is underdamped. To make it overdamped, the value of R ______.
has to be increased
If the steel disk in a crankshaft position sensor has stopped with the tab in the magnet's air gap, the induced voltage ______.
is zero
In an R-C series circuit excited by a voltage E, the charge across capacitor at t = 0^+ is ______
0
In figure shown, what is the current supplied by battery immediately after switching on the circuit?
1 A
In an ac circuit, what can be the maximum and minimum values of power factor?
1 and 0
For the circuit shown below, different time constants are given: 1. 0.5 x 10¯³ s 2. 2 x 10¯³ s 3. 0.25 x 10¯³ s 4. 10¯³ s What are the charging and discharging times respectively?
1, 3
What if you have a 12-strand conductor and each strand has a radius (one-half the diameter) of 2/10 inch, what is the square mil area of the conductor?
1,507,965 sq. mil
For all resistor wattage ratings except 1/8 watt, what is the maximum allowable change in resistance for a 1000-hour rated load life test?
10%
The figure shows the self-bias circuit for CE amplifier and its equivalent circuit. What are V_BB and R_B respectively?
2 V and 4 kΩ
Si transistor of the following figure has a α = 0.9 and I_CE = 0, V_EE = 5 V and Vcc = 13 V, then R_E will be ____ if I_EQ = 1 mA.
4.3 kΩ
In the circuit shown below, the silicon npn transistor Q has a very high value of β. What is the required value of R2 in kΩ to produce Ic = 1 mA?
40
In figure shown, v1 = 8 V and v2 = 4 V. Which diode will conduct?
D₁ only
In figure shown, what is the saturation collector current?
Vcc/Rc + R_E
A capacitor terminology that refers to minute and rapid fluctuations of capacitance?
Scintillation
When a current source I is suddenly connected across a two terminal relaxed RC circuit at time t = 0, the voltage across the current source is shown in figure. The RC circuit is ______.
a series combination of R and parallel combination of R and C
In a CE amplifier the input impedance is equal to the ratio of _______.
ac base voltage to ac base current
The B-H curve for _____ will be a straight line passing through the origin.
hardened steel
The drift velocity of electrons is ______.
very small as compared to speed of light
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?
The input resistance Ri increases and the magnitude of voltage gain Av decreases