Description : What is the typical back-to-forward resistance ratio of a good-quality diode?
Last Answer : 10-to-1 ratio.
Description : In a photocell light, energy is converted into
Last Answer : Electric Energy
Description : In a photocell light energy is converted into – (1) Potential energy (2) Chemical energy (3) Heat energy (4) Electrical energy
Last Answer : (4) Electrical energy Explanation: Photocells are scientifically known as photo-resistors. A photo-resistor or light dependent resistor (LDR) is a resistor whose resistance decreases with increasing ... by the semiconductor give bound electrons enough energy to jump into the conduction band.
Description : In a photocell light energy is converted into (1) potential energy (2) chemical energy (3) heat energy (4) electrical energy
Last Answer : electrical energy
Description : Explain the construction and working of a photocell. State its any two applications.
Last Answer : Construction: 1. It consists of evacuated glass bulb having cathode (K) and anode (A). 2. The semi cylindrical cathode coated with photosensitive material from inner side. 3. The anode is platinum rod. 4. The ... in Burglar alarm. 4) It is used in TV set. 5) It is used in fire alarms.
Description : Photocell and solar cell difference?
Last Answer : A photo cell is a light dependent resistor which decreases it resistance high intensity of light and is used to automatically control lights etc where as a solar cell solar or light energy into electrical energy.
Description : Draw a neat labelled diagram of photocell and state two properties of photons.
Last Answer : Properties of Photon: 1) Photon is electrically neutral. 2) Photon travels with speed of light. 3) Photon do not ionized. 4) Photon has rest mass zero. 5) Photon cannot be deflected by electric or magnetic ... has momentum term h / λ 7) Photon has definite packets of energy given by E = hʋ
Description : When you are testing the gain of an audio-frequency transistor with an ohmmeter, what is indicated by a 10-to-1 resistance ratio?
Last Answer : Normal gain.
Description : As a rule of thumb, what is an acceptable ratio of back-to forward resistance for a diode?
Last Answer : Greater than 10 to 1
Description : What the three basic components make up the typical magnetic amplifier?
Last Answer : Two saturable reactors and a transformer.
Description : In a typical velocity servo block diagram what device is placed in the feedback loop that is not present in the position servo?
Last Answer : Tachometer.
Description : A typical liquid-cooling system is composed of what loops?
Last Answer : Primary and secondary.
Description : What is the typical frequency range about the center frequency of a tunable magnetron?
Last Answer : . ±5 percent.
Last Answer : ±5 percent.
Description : A typical satellite communications operational link consists of a satellite and what two other components?
Last Answer : Earth terminals.
Description : The LED lamps of a typical logic probe are normally in what state?
Last Answer : DIM.
Description : Name the three main sections of a typical rf signal generator.
Last Answer : Oscillator circuit, modulator, and output control circuit.
Description : What are the two major sections of a typical AM transmitter?
Last Answer : Rf and af units.
Description : Will dark current increase or decrease as the temperature of the photodiode increases?
Last Answer : Increase.
Description : What is the dark current?
Last Answer : The leakage current that continues to flow through a photodetector when there is no incident light.
Description : True statements about EOG (electro-oculogram) include: a. the EOG light-peak to dark-trough ratio is reduced in central retinal vein occlusion b. the light peak of EOG is abnormal in Best' ... rise is produced by depolarization of the basal membrane of the retinal pigment epithelium d. all above
Last Answer : all above
Description : What sensor provides a change of resistance with typical power range of 1uW to 10mW and with maximum frequency greater than 100GHz
Last Answer : thermistor sensor
Description : The typical ratio of latching current to holding current in a 20A thyristor is : (A) 5.0 (B) 2.0 (C) 1.0 (D) 0.5
Last Answer : The typical ratio of latching current to holding current in a 20 A thyristor is 2.0
Description : What is an advantage of using a resistance soldering iron when soldering wire to a connector?
Last Answer : The soldering tips are hot only during the brief period of soldering the connection, thus minimizing the chance of burning the wire insulation or connector inserts.
Description : When you are using an ohmmeter to test a transistor for leakage, what is indicated by a low, but not shorted, reverse resistance reading?
Last Answer : A leaking transistor
Description : Which transistor configuration has the highest input resistance?
Last Answer : Common collector.
Description : When a bridge is used to measure resistance, what is the value of Rx if R1 equals 80 ohms, R2 equals 120 ohms, and R3 equals 280 ohms?
Last Answer : 420 ohms.
Description : What is the resistance level of a photodiode in total darkness?
Last Answer : Very high.
Description : What resistance property is found in tunnel diodes but not in normal diodes?
Last Answer : Negative resistance.
Description : A shunt-type voltage regulator is connected in serial/parallel (which one) with the load resistance.
Last Answer : In parallel.
Description : When a series voltage regulator is used to control output voltages, any increase in the input voltage results in an increase/a decrease (which one) in the resistance of the regulating device.
Last Answer : An increase.
Description : When checking a diode with an ohmmeter, what is indicated by two high resistance measurements?
Last Answer : The diode is open or has a high-forward resistance.
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 : A shunt type voltage regulator is connected in series/parallel with the load resistance.
Last Answer : Parallel
Description : When a series voltage regulator is used to control output voltages, any increase in the input voltage results in an increase/a decrease in the resistance of the regulating device.
Description : As the dissipated power increases, what effect does this have on the resistance of a thermistor?
Last Answer : . It increases.
Description : The point on the current curve of a gallium-arsenide semiconductor at which it begins to exhibit negative resistance is called what?
Last Answer : Threshold.
Description : What causes the negative-resistance property of tunnel diodes?
Last Answer : The tunneling action
Description : Why is the negative-resistance magnetron often operated with reduced filament voltage?
Last Answer : To reduce the effects of filament bombardment.
Description : What starts the oscillations in a negative-resistance magnetron?
Last Answer : The application of the proper magnetic field.
Description : A carbon resistor has a resistance of 50 ohms, and a tolerance of 5 percent. What are the colors of bands one, two, three, and four, respectively?
Last Answer : The bands are green, black, black, and gold.
Description : What is the relationship between conductance and resistance?
Last Answer : They are reciprocals of each other.
Description : What term describes a material whose resistance remains relatively constant with changes in temperature?
Last Answer : Zero temperature coefficient.
Description : Which temperature coefficient indicates a material whose resistance increases as temperature increases?
Last Answer : Positive.
Description : Which wire has the least resistance? Wire A-copper, 1000 circular mils, 6 inches long. Wire B-copper, 2000 circular mils, 11 inches long.
Last Answer : Wire B.
Description : Compare the resistance of a conductor to that of an insulator.
Last Answer : Conductors have a very low resistance and insulators have a resistance that is so great that, for all practical purposes, they are nonconductors.
Description : What happens to the resistance of copper when it is heated?
Last Answer : It increases.
Description : Define the temperature coefficient of resistance.
Last Answer : The amount of increase in the resistance of a 1-ohm sample of the conductor per degree of temperature rise above 0º C
Description : Using table 1-2, determine the resistance of 1,500 feet of AWG 20 wire at 25º C.
Last Answer : 1,000 ft = 10.4 ohms1,500 ft = 1.5 × 0.4 = 15.6 ohms
Description : List the three factors used to calculate resistance of a particular conductor in ohms.
Last Answer : Length, cross-sectional area, and specific resistance of a unit volume of the substance from which the conductor is made