PHY208 List of eExam Questions in the Bank

Latex formatted questions may not properly render

Q1 Attenuation is measured in units of

Q2 Attenuators used with coaxial lines are the form while attenuators for use with twisted pair are required to be the form.

Q3 Frequency bandwidth is expressed in units of

Q4 A filter in which the signal passes through an inductor, or in which a capacitor provides a path to ground, presents less attenuation to low-frequency signals than high-frequency signals and is a filter

Q5 Linear filters whose implementation is based on the combination of resistors (R), inductors (L) and capacitors (C) are collectively known as filters

Q6 For a series RLC circuit, if $$f=\frac{1}{2\pi\sqrt{LC}}$$, $$f$$ is the frequency

Q7 In a series RLC circuit, the capacitive reactance causes total current to the applies voltage.

Q8 The electrical properties of semiconductors can be modified by addition of impurities to the pure semiconductor substrate. This process is known as

Q9 For reactive loads, maximum power transfer takes place when the source impedance is the complex of the load impedance

Q10 Electrical impedance has both magnitude and angle

Q11 The impedance of a lossless idealized network element is referred to as

Q12 The conduction mechanism in semiconductors is contributed to by both electrons and

Q13 Circuit elements which have a linear voltage to current relationship and which obey Ohm’s Law are referred to as devices

Q14 An electronic device that reduces the amplitude or power of a signal without appreciably distorting its waveform is called

Q15 An filter consists of two reactive elements, one in series and one in parallel

Q16 A narrow region around the PN junction formed by the diffusion of majority carriers across the junction is called the layer.

Q17 In a linear network, having several sources (which include the equivalent source due to initial conditions), the overall response, at any point in the network, is equal to the sum of individual responses of each source considered separately, the other sources being made inoperative. This the theorem of electrical network

Q18 "Insofar as load is concerned, any one-port network of resistance elements and energy sources can be replaced by a series combination of an ideal voltage source V and resistance R, where V is the open-circuit voltage of the one-port and R is the ratio of the open-circiut voltage to the short-circuit current". This is theorem

Q19 If a parallel combination of $$12\Omega$$ and $$6\Omega$$ resistances is connected to a series combination a $$42V$$ d.c. source and a $$3\Omega$$ resistance, the current in the $$12\Omega$$ resistance (to the nearest whole number) is A

Q20 Two one-ports are if they present the same v-I characteristics

Q21 The statement "the algebraic sum of the currents into a node at an instant is zero" is current

Q22 Is a Klystron a Vacuum Tube?

Q23 the two types of bipolar juction transistors are and transistors

Q24 The dual of an N Channel field effect transistor is a channel field effect transistor

Q25 Germanium, Silicon, Gallium Arsenide and Silicon Carbide are all examples of materials

Q26 If a twisted pair transmission line is balanced write BALANCED, otherwise write UNBALANCED in this space provided

Q27 The theorem which is frequently called “the parallel generator theorem” is the theorem

Q28 Another name for Maximum Power theorem is law

Q29 At resonance, the and reactances of an LC circuit are equal

Q30 The theorem which states that the reactance of a passive, lossless one-port network always monotonically increases with frequency is called the reactance theorem

Q31 A bipolar junction transistor is basically a - terminal device

Q32 Transistors are generally classified as and transitors

Q33 The diode is used for the construction of a voltage regulator

Q34 The conection of the positive terminal of a battery to the P-side and negative terminal to the N-side of a PN junction is referred to as bias

Q35 The process whereby a AC voltage is converted to a unidirectional (DC) voltage is refered to as

Q36 The early electronic devices (diodes, triodes, etc) depended on effect for the generation of current carriers (electrons)

Q37 The first diodes were made of tubes

Q38 Energy stored in the form of a magnetic field or a moving charge in the

Q39 Which of the following circuit quantities is employed in the storage of energy? (resistance, capacitance, conductance, resistivity)

Q40 Given that $$i=Gv$$, where $$i$$ is the current and $$v$$ is the potential difference, then the unit of $$G$$ is (ohms, siemens, ampres, volts)

Q41 The electron gun of a cathode ray tube provides a beam of high velocity electron. If the electrons are accelerated through a potential difference of 20 000 eV over adistance of 4 cm, then the field strength is $$\times{10^{5}} V/m$$ (2, 3, 4, 5)

Q42 The quantity $$\int \vec{B}\cdot{d}\vec{A}$$ defines the (magnetic flux density, electric current density, magnetic field strength, magnetic flux)

Q43 the potential gradient is a measure of the (electric current, magnetic flux density, electric flux, electric field strength)

Q44 The energy transfer capability of the flow of electric charge is determined by the through which the charge moves (resistance, potential difference, impedance, current)

Q45 A circuit device which changes or information to another is called (transducer, modulator, oscillator, amplifier)

Q46 When the dimensions of a network component s unimportant and its total effect can be considered to be concentrated at a poin, then the component can be represented by a parameter (lumped, distributed, continuous, discrete)

Q47 A transistor , device (active, linear; passive, nonlinear; passive, linear; active, non-linear)

Q48 A two- terminal device is a - port (one, two, three, four)

Q49 Transistors are -ports. (tow, three, four, one)

Q50 A diode is a - terminal device (one, two, three, four)

Q51 The principal element of a rectification circuit is the-------





Q52 The term 'reverse bias' as applied to the conection of a PN junction implies





Q53 The gain of an amplifier is usually maesured in ------------





Q54 In a public address system, which of these devices produces a louder human voice?





Q55 Which of the following is an ohmic device?





Q56 To identify an NPN transistor from its symbol, we must note that ------------





Q57 The emitter of a bipolar junction transistor is generally the more heavily dopedrelative the base and the collector because it





Q58 The electric current density $$\vec{J}$$ is equal to





Q59 Nullator is a circuit element that





Q60 The unit of inductance is ?





Q61 For maximum power transfer, the optimum load impedance must be equal to ------------ of the source impedance





Q62 Which Idealised Circuit Element presents an impedance phase angle which is equal to zero degrees?





Q63 To calculate the net charge through a circuit configuration in which there is a current induced by a variable magnetic field, which of the following laws can be used?





Q64 In which of the following types of circuit elements is there no phase difference between voltage and current





Q65 Kirchhoff's loop rule is a statement of the conservation of --------





Q66 A series RLC circuit consists of $$50\Omega$$ resistance, 0.2 H inductance and $$10\mu{F}$$ capacitor with the applied voltage of 20 V, Determine the resonant frequency.





Q67 Which of the following correctly defines the impedance function of a parallel resonant LC circuit?





Q68 In a circuit, consisting of a $$1k\Omega$$ resistor connected in series with 50 mH coil, a 10V rms, 10 kHz signal is applied. Find the impedance Z





Q69 A two-terminal linear active network may be replaced by a voltage source in series with an impedance. The emf of the voltage source is the open-circuit voltage at the terminals and the impedance (Z) is that viewed at the terminals when all the generators in the network have been replaced by their internal impedances. This is the statement of _____________'s theorem





Q70 Which of the following terminals does not belong to th bipolar junction?





Q71 The statement that "the imaginary immittance of a passive, lossless one-port monotonically increases with frequency" is ------------------------ theorem





Q72 Vacuum tubes are devices that operate based on the principle of _____________ emission





Q73 If an emf E is placed in one branch of an electrical circuit, giving rise to a current in another branch, the same current is obtained in the original branch when the emf E is transferred to the branch where the current arose. This the ----------------- theorem





Q74 Determine V for the circuit shown





Q75 Which of the following is a linear element of a circuit?





Q76 Which of the following circuit elements can be described as unidirectional





Q77 Which of these can store finite amount of energy?





Q78 Kirchhoff's current law is a statement of the conservation of --------





Q79 Which of the following is an active element of a circuit





Q80 Which of the following is NOT one of the broad classificarion of network elements





Q81 What is the unit of measurement of conductance?





Q82 Determine cut off frequency for the Low Pass filter shown in the Figure





Q83 Which of the following is not a relationship between voltage and current?





Q84 What was the first Vacuum tube invented?





Q85 Determine cut off frequency for the Low Pass filter shown in the Figure





Q86 What is the Maximum Power that can be drawn by a load from a voltage source?





Q87 How many ports does a Delta Network have?





Q88 Which of these theorems is frequently called “the parallel generator theorem”.





Q89 The practice of designing the input impedance of an electrical load or the output impedance of its corresponding signal source in order to maximize the power transfer and minimize reflections from the load is known as impedance ---------------------





Q90 Attenuation is usually expressed in units of





Q91 If the current in the figure $$i=5e^{-2t}A$$ flows in an intially uncharged $$0.25-F$$ capacitance ($$v_{C}=0$$ at $$t=0$$), determine the voltage $$v_{C}(t)$$.





Q92 An alternative to impedance matching is impedance _____________





Q93 An electronic device that reduces the amplitude or power of a signal without appreciably distorting its waveform and are usually passive devices made from simple voltage divider networks is called -------------------





Q94 The propagation constant of a symmetrical $$\pi{- network}$$ is the same as that for a symmetrical $$T-network$$ and is given by





Q95 A filter which passes frequencies between two designated cut off frequencies and attenuates all other frequencies is called --------------- pass





Q96 The circuit shown is ------------------------ section fiter





Q97 A reactive network that freely passes the desired bands of frequencies while almost totally suppressing all other bands is called a ------------------------





Q98 The range of frequencies for which the current or output voltage is equal to 70.7% of its peak value at the resonant frequency is known as the ----------------





Q99 A sine wave generator supplies a 500 Hz, $$10V_{rms}$$ signal to a $$2 k\Omega$$ resistor in series with $$0.1\mu{F}$$ capacitor. Determine the phase angle $$\theta$$





Q100 A sine wave generator supplies a 500 Hz, $$10V_{rms}$$ signal to a $$2 k\Omega$$ resistor in series with $$0.1\mu{F}$$ capacitor. Determine the total impedance Z.