Description : A measure of conversion efficiency of a photodetector. ∙ A. Efficiency ∙ B. Responsivity ∙ C. Dark current ∙ D. Spectral response
Last Answer : B. Responsivity
Description : The time constant of a first order process with resistance R and capacitance C is (A) R + C (B) R - C (C) RC (D) 1/RC
Last Answer : (C) RC
Description : Is an RC filter used when a large current or a small current demand is required?
Last Answer : Small.
Description : Trade-offs between competing effects are necessary for high speed response. Which competing effect (fast transit time, low capacitance, or high quantum efficiency) requires a thin active area?
Last Answer : Fast transit time.
Description : What is the RC time constant of a series RC circuit that contains a 12-megohm resistor and a 12-microfarad capacitor?
Last Answer : 144 seconds (t=R x C)
Description : In a sawtooth generator, why is the transistor turned on for a longer time than the discharge time of the RC network?
Last Answer : To allow the capacitor time to discharge.
Description : If charge stored on plates of capacitor is large, then capacitance will be A. small B. large C. zero D. infinite
Last Answer : large
Description : What is the difference between an RC and an RL differentiator in terms of where the output is developed? is developed?
Last Answer : . In an RC circuit the output is taken across the resistor. In the RL circuit the output is taken across the inductor.
Description : When is a second RC filter stage used?
Last Answer : When ripple must be held at an absolute minimum.
Last Answer : When ripple must be held at an absolute minimum
Description : Which RC network provides better frequency stability, three-section or four-section?
Last Answer : Four-section.
Description : What is the voltage drop across the resistor in an RC charging circuit when the charge on the capacitor is equal to the battery voltage?
Last Answer : Zero.
Description : At what instant does the greatest voltage appear across the resistor in a series RC circuit when the capacitor is charging?
Last Answer : At the instant of the initiation of the action.
Description : What is the greatest limiting factor in a receiver’s detectable range
Last Answer : Noise.
Description : Fiber-to-fiber coupling loss is affected by intrinsic and extrinsic coupling losses. Can intrinsic coupling losses be limited by limiting fiber mismatches?
Last Answer : Yes.
Description : What method for encoding digital data enables you to store more data in less space by limiting the distance between pulses on a hard disk?
Last Answer : Run length-limited (RLL) encoding.
Description : What is the limiting factor as to the amount of current an electrodynamometer meter movement can handle?
Last Answer : Size of spiral conducting.
Description : In the illustrated circuit, one advantage of the capacitor coupling over direct coupling is ____________. EL-0048 A. as the frequency decreased the capacitive reactance (Xc) increases B. the amplifier becomes ... of the signal while it isolates the biasing of each stage. D. good frequency response.
Last Answer : Answer: C
Description : What type of feedback is usually caused by the base-to collector interelectrode capacitance?
Last Answer : Degenerative or negative
Description : What type of feedback is usually caused by interelectrode capacitance?
Last Answer : Negative (degenerative) feedback
Description : When an unknown capacitance is tested with a bridge, what is the value of Cx if R1 equals 70 ohms, R2 equals 150 ohms, and Cs equals 550 microfarads?
Last Answer : 256 microfarads.
Description : What effect does an increase in capacitance have on a capacitor’s opposition to current flow?
Last Answer : Opposition to current flow decreases.
Description : When the reverse bias on a varactor is increased, what happens to the effective capacitance?
Last Answer : Capacitance decreases.
Description : A transmission line is said to have distributed constants of inductance, capacitance, and resistance along the line. What units of measurement are used to express these constants?
Last Answer : Inductance is expressed in micro henrys per unit length, capacitance is expressed in picofarads per unit length, and resistance is expressed in ohms per unit length.
Description : . What are two of the three physical factors that determine the values of capacitance and inductance of a transmission line?
Last Answer : (1) Type of line used, (2) dielectric in the line, and (3) length of line.
Description : Moving tube electrodes apart to decrease interelectrode capacitance causes an increase in the effect of what property?
Last Answer : Transit time
Description : What happens to the impedance of interelectrode capacitance as frequency increases?
Last Answer : Impedance decreases.
Description : How does the addition of a screen grid in a tetrode reduce interelectrode capacitance?
Last Answer : The interelectrode capacitance (cpg) is divided between two series capacitances; thus, cpg is greatly reduced.
Description : What happens to the value of XC as capacitance increases
Last Answer : XC decreases.
Description : Examine the three capacitors shown below. What is the capacitance of each?
Last Answer : a. 26µF or 260,00pF b. 630pF c. 9600pF
Description : State three factors that affect the capacitance of a capacitor.
Last Answer : a. The area of the plates. b. The distance between the plates. c. The dielectric constant of the material between the plates.
Description : What method is used to prevent oscillations in large synchro units?
Last Answer : Mechanical damping.
Description : What structurally large, low-resistance conductor is connected in parallel with the meter movement to prevent damage?
Last Answer : Shunt.
Description : RC time constant characteristics, as shown in the illustration, are important in _____________. EL-0086 A. bridge rectifiers for alternator excitation B. timing and pulse shaping circuits C. transistor power amplifier biasing D. motor controller overload protection
Last Answer : Answer: B
Description : The diagram shown in the illustration demonstrates one of the useful properties of an 'RC' time constant circuit. The useful characteristic of the circuit is that 'C' can be charged ________________. EL-0086 A. ... with a high 'R' value and discharged slowly at a low current with a low 'R' value
Last Answer : Answer: A
Description : Time constant for RC circuit formula τ = RC Where, τ = time constant
Last Answer : Time constant for RC circuit formula τ = RC Where, τ = time constant
Description : The time constant of an RC circuit is defined as the time taken by the voltage across the capacitor to become_____ of its final value (a) 63.2% (b) 36.8% (c) 50% (d) 100%
Last Answer : The time constant of an RC circuit is defined as the time taken by the voltage across the capacitor to become 63.2% of its final value
Description : Limiting reactant in a chemical reaction decides the (A) Rate constant (B) Conversion (C) Reaction speed (D) Equilibrium constant
Last Answer : (B) Conversion
Description : In the case of steady flow of a fluid, the acceleration of any fluid particle is (A) Constant (B) Variable (C) Zero (D) Zero under limiting conditions
Last Answer : Answer: Option C
Description : Find the time constant of a capacitor with capacitance of 2 microfarad having an internal resistance of 4 megaohm. a) 2 b) 0.5 c) 8 d) 0.25
Last Answer : c) 8
Description : The time constant of the capacitance circuit is defined as the time during which voltage?
Last Answer : The time constant of the capacitance circuit is defined as the time during which voltage rises to 63.2% of its final steady value.
Description : A capillary tube is kept vertical in a beaker containing liquid. The height to which the liquid rises by capillary action is increased if (a) The radius of the capillary is large (b) The radius of the ... small (c) The density of the liquid is large (d) The surface tension of the liquid is small
Last Answer : Ans:(b)
Description : The size of mould for bricks, is generally kept (A) A little large to specified size (B) A little small to specified size (C) Equal to specified size (D) 10% larger than specified size
Last Answer : Answer: Option A
Description : Which of the following parameters is not a primary parameter? a) Resistance b) Attenuation constant c) Capacitance d) Conductance
Last Answer : Ans: B
Description : An AC circuit has capacitance arranged in series. If the line voltage remains constant, the capacitive reactance value can be varied by changing the _____________. A. line frequency B. resistance C. number of commutating poles D. number of interpoles
Description : Referred to the dielectric constant of a transmission line material. A. Inductance and capacitance B. Velocity factor C. Characteristic impedance D. Propagation velocity
Last Answer : B. Velocity factor
Description : When a large signal and a small signal are applied to a lin log amplifier at the same time, what is the effect on the small signal?
Last Answer : Amplification is reduced.
Description : When a megohmmeter is used to test the insulation of a large motor, the initial dip of the pointer toward 'zero' is caused by ____________. A. good insulation B. the capacitance of the ... of the current along the surface of dirty insulation D. the dielectric-absorption effect of the insulation