Electronics Engineering Test Question

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ELECTRONICS ENGINEERING TEST QUESTIONSunday, October 19, 2008Electronic Test 10 Volume 1

1. The voltage across two resistors are equal when they are connected in A. series (B) parallel C.parallel-series D. series-parallel 2. The currect is zero in all resistors connected in series when one resistor is A. leaky B. shorted (C) opened D. 0 3. The physical motion resulting from the forces of magnetic fields is called (A) motor action B. Faradays law C. torque D. Lenzs law 4. The voltage output of a cell depends on its A. size B. construction C. type (D) elements 5. What is the most common type of dry cell? A. Leclanches cell B. Carbon-zinc C. Lithium cell (D) Both A and B

6. With the common collector amplifier, A. the input impedance is low B. the power gain is always less than 1 C. current gain is always less than 1 (D) voltage gain is always less than 1 7. Superconductivity occurs in certain substances A. only when they are in liquid state (B) only at very low temperatures C. only at very high temperature D. at all temperatures 8. Of the following quantities, the one that is vector in character is electric A. energy B. charge (C) field D. current 9. The elcectron in an atom (A) are some distance away from the nucleus B. are bound to its permanently C. have more mass than the nucleus D. may be positively or negatively charged 10. In a transistor oscillator, ______ is the active device. A. biasing circuit (B) transistor C. LC tank circuit D. PN junction 11. If the doping level is increased, the breakdown voltage of a zener (A) is decreased B. is increased C. remains the same D. becomes infinite 12. Which of the following statements is false? (A) The proton and neutron have the same mass. B. The electron and proton have different masses. C. The electrons and protons have charges of the same magnitude but opposite in sign. D. Atomic nuclei contain only protons and neutrons. 13. Which of the following is neither a basic physical law or derivable from one? A. Coulombs law (B) Ohms law C. Kirchhoffs first law D. Kirchhoffs second law 14. When a pure semiconductor is heated, its resistance (A) goes down B. goes up C. remains the same D. becomes zero 15. The gain of the amplifier with feedback is known as

A. open loop gain (B) closed loop gain C. feedback gain D. regenerative gain 16. In an ac circuit, the voltage A. leads the current B. lags the current C. is in phase with the current (D) is any of the above 17. The power dissipated as heat in an ac circuit depends on (A) resistance B. inductive reactance C. capacitive reactance D. impedance 18. The emf produced in a wire by its motion across a magnetic field Does not depend on A. the length of the wire (B) the diameter of the wire C. the orientation of the wire D. the flux density of the field 19. Eddy currents occur only in A. ferromagnetic materials (B) conductors C. insulators D. coils 20. Lenzs law is a consequence of the la of conservation of A. charge B. field lines C. momentum (D) energy 21. All magnetic fields originate in A. iron atoms B. permanent magnets C. magnetic domains (D) moving electric charges 22. The resistance of a conductor does not depend on its (A) mass B. length C. cross-section area D. resistivity 23. The ripple will _______ if the filter capacitance is increased. (A) decrease B. stay the same C. increase D. become zero 24. Self-bias produces (A) positive feedback B. negative feedback

C. reverse feedback D. forward feedback 25. The field effect transistor when compared to bipolar has much more A. current B. voltage gain (C) input resistance D. supply voltage 26. Voltage gain is defined as the ratio of output voltage to (A) input voltage B. ac emitter resistance C. ac collector resistance C. generator voltage 27. What is the error voltage of an ideal op- amplifier? A. Very small B. Very large (C) Zero D. Equal to input voltage 28. What is the form of the schematic symbol an op-amplifier? A. A square B. A circle (C) A triangle D. A rectangle 29. Which resistor is good in radio amplifier application? A. Silver mica B. Wirewound C. Tantalum (D) Carton composition 30. Which does not denote a type a capacitor? A. Silver-mica B. Air variable (C) Ferrite D. Tantalum Posted by marvelyn at 12:03 AM 0 comments

Friday, October 17, 2008Electronic Test 9 Volume 1

1. The action of a JFET can be compared with that of a A. pentode B. tetrode (C) triode D. diode 2. What is the equivalent binary of the octal number 673? A. 101111101 (B) 110111011 C. 110110101 D. 110111111 3. What is the value of the upper resistance limit of a resistor with color-coding of Brown, Black, Black, Gold? A. 105 B. 1.5 (C) 10.5 D. 150 4. How do we obtain the time constant of a series inductor and resistor circuit? (A) By dividing the resistance value by the inductance value B. By multiplying the inductance value by the resistance value C. by dividing the inductance value by the resistance value

D. By dividing the inductance value by the conductance value 5. How to test whether an oscillator is generating an output? (A) By checking that the drain current is flowing B. By checking the value of the signal bias on the gate C. By checking that the source current is flowing D. By checking for a high value of the dc supply voltage 6. What is the time constant of a circuit with a charged capacitor connected across a resistor? (A) The time required for the capacitor to discharge to a certain Percentage of its initial voltage B. Equal to the value of the capacitance divided by the resistance C. Is the half-life of the capacitor when shunted by the resistor D. Is equal to the natural period of the circuitss oscillation 7. How is the frequency of a transistorized multivibrator determined? A. By the parameters of the transistor (B) By the junction capacitance of the transistor C. By the collector supply voltage D. By the time constants formed by the coupling capacitors and the base resistors. 8. When an atom gains an additional electron ______results. A. positive (B) negative C. negative molecule D. negative neutron 9. Which configuration provides a high degree of isolation between two stages? A. Common base B. Common emitter C. Common collector (D) Common grid 10. The impedance of an ac circuits measured in A. farads B. henrys C. siemens (D) ohms 11. What is the equivalent hexadecimal number of the binary number 11100101111? A. 72E (B) 72F C. 73F D. 82E 12. Which electrode of a triode tube can be compared with the base region of a bipolar transistor? (A) Control grid B. Filament C. Cathode D. Screen grid

13. Which of the following logic circuits has an operation that corresponds to two or more switches (or relays) in series? (A) XOR gate B. NAND gate C. AND gate D. NOR gate 14. Which circuit components has the highest failure rate under normal Conditions? A. Transformer B. Transistor C. Resistor (D) Capacitor 15. The inductance of a coil with an air core is directly proportional to the A. length of the core (B) number of turns C. square of the number of turns D. cross-sectional area of the wire 16. What is the effect if a bleeder resistor burns out in a power supply during normal operation? (A) The diodes could be destroyed B. The percentage regulation increases significantly. C. There is no appreciable effect on the output dc voltage. D. The power transformer will be damaged unless it protected by a fuse. 17. The peak value of a sine wave having an effective value of 20 V is A. 70.7 V B. 14.1 V C. 56.6 V (D) 28.3 V 18. A varistor is a semiconductor device A. that can be used to achieve voltage regulation B. Whose resistance is controlled by the applied voltage C. that has a high positive temperature coefficient (D) both A and B correct 19. If a tank ciruit is at the load of a class C amplifier, the (A) input signal is small B. efficiency is low C. output voltage waveform is severely distorted D. output current waveform is severely distorted 20. The effective values of the source voltage and the source current are kept constant in an ac circuit. Initially, the current and voltage are in phase, but as they move out of phase, are (A) power factor increases B. apparent power increases C. true power decreases D. reactive power decreases 21. What is the total available emf of twelve nickel-cadmium cells that are connected in series?

A. 12 V B. 24 V C. 2.05 V (D) 15 V 22. What is the resonant frequency of a series RLC circuit consisting of a 6- resistor, a 5- H inductor and a 5-pF capacitor? A. 3.18 MHz (B) 31.8 MHz C. 31.8 kHz D. 318 MHz 23. A difference of potential may also be described as A. electric power (B) voltage C. amperage D. electron drift 24. A non-conductor is characterized by A. very few electrons (B) high energy dissipation C. a large number of free electrons D. large amount of skin effect. 25. A wattmeter automatically compensates for A. power factor B. overdamping C. line resistance (D) power losses 26. RMS is related to peak voltage by the decimal A. 0.0707 B. 0.636 (C) 0.707 D. 0.770 27. What is the chemical composition of the electrolyte of a lead-acid storage cell? A. Sulphur dioxide acid (B) Sulphuric acid C. Lead sulphate acid D. Hydrochloric acid 28. What is usually employed by an RF voltage amplifier as opposed to an RF power amplifier? A. Class A bias (B) Class C bias C. Cut-off bias D. Zero bias 29. The transistor common-base amplifier is similar To what configuration of a vacuum tube? (A) Grounded-grid amplifier B. Video amplifier C. Cathode-follower amplifier D. Audio amplifier

30. ______ determines the speed of a dc series motor. A. The brush tension (B) The field current C. The load D. The number of pairs of poles Posted by marvelyn at 5:33 AM 0 comments

Electronic Test 8 Volume 1

1. A group of circuits that provides timing and signals of all operations in the computer. A. Output unit (B) Memory unit C. Control unit D. Input uni