ELEX RC 3

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? a) 1, 3 b) 2, 3 c) 2, 4 d) 1, 2

a) 1, 3

All but which one of the following statements regarding extrinsic semiconducting silicon is true? Electrons are donated to the conduction band in n-type silicon. The Fermi energy is raised by Group V elements in extrinsic silicon. Group III elements accept electrons from the valence band of silicon. The number of n-type carriers equals the number of p-type carriers in extrinsic silicon.

The number of n-type carriers equals the number of p-type carriers in extrinsic silicon.

An RLC series circuit is underdamped. To make it overdamped, the value of R ______. has to be reduced to zero has to be decreased has to be increased to infinity has to be increased

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 ______. increases will remain constant decreases is zero

is zero

The drift velocity of electrons is ______. equal to speed of light very small as compared to speed of light half the speed of light almost equal to speed of light

very small as compared to speed of light

In an R-C series circuit excited by a voltage E, the charge across capacitor at t = 0^+ is ______ CE CE [1 - e^(t/RC)] 0 infinity

0

In figure shown, what is the current supplied by battery immediately after switching on the circuit? 4 A 10 A 0 1 A

1 A

In an ac circuit, what can be the maximum and minimum values of power factor? 1 and 0 2 and 0 0 and -1 1 and -1

1 and 0

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? 61,115 sq. mil 45,239 sq. mil 244,344,097 sq. mil 1,507,965 sq. mil

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% 5% 15% 12%

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 10 kΩ 5 V and 4 kΩ 2 V and 4 kΩ 10 V and 4 kΩ

2 V and 4 kΩ

7. 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 5 kΩ 3 kΩ 4 kΩ

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 50 30 20

40

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? 400 100 300 200

400

In figure shown, v1 = 8 V and v2 = 4 V. Which diode will conduct? D2 only D1 only Neither D1 nor D2 Both D1 and D2

D1 only

A capacitor terminology that refers to minute and rapid fluctuations of capacitance? Burnout Capacitance proofing Coronation Scintillation

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 parallel combination of R and C a series combination of R and C a pure capacitor a series combination of R and parallel combination of R and C

a series combination of R and parallel combination of R and C

What is the rms value of the wave shown in the figure? about 25 V about 95 V about 50 V about 80 V

about 80 V

In a CE amplifier the input impedance is equal to the ratio of _______. ac emitter voltage to ac collector current ac base voltage to ac emitter current ac collector voltage to ac collector current ac base voltage to ac base current

ac base voltage to ac base current

The B-H curve for _____ will be a straight line passing through the origin. silicon steel soft iron hardened steel air

air

To prevent a DC return between source and load, it is necessary to use _______. capacitor between source and load inductor between source and load either resistor between source and load or inductor between source and load resistor between source and load

capacitor between source and load

If the cross-sectional area of a magnetic field increases, but the flux remains the same, the flux density _______. increases remains the same doubles decreases

decreases B=0/A

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? (nasa ans ang diagram) Both input resistance Ri and the magnitude of voltage gain Av increase The input resistance Ri decreases and the magnitude of voltage gain Av decreases The input resistance Ri increases and the magnitude of voltage gain Av decreases Both input resistance Ri and the magnitude of voltage gain Av decrease

The input resistance Ri increases and the magnitude of voltage gain Av decreases