A 230 V, 500 rpm, 100 A separately- excited dc motor has an armature resistance of 0.1 ohms. The motor is driving, under rated conditions, a load whose torque is constant and independent of speed. The speeds below the rated speed are obtained with armature voltage control (with full field) and the speeds above the rated speed are obtained by field control (with rated armature voltage).

1. What motor terminal voltage is needed to run it at 400 rpm?

2. By what amount should flux be reduced to get a motor speed of 800 rpm?

Neglect the motor’s rotational losses.

3.The separately- excited motor of the previous problem is now coupled to an overhauling load with a torque of 800 N-m. Determine the speed at which the motor can hold the loadby regenerative braking. Source voltage is 230 V. Neglect the motor’s rotational losses.

In set-associative mapping, why when having the choice to replace of which cache line to replace do we choose the ones with D=0?

How would you design a counter with repeating states? (use whichever flip flop is easiest)

I will give "easy" examples

1a) 0-0-1-2-3

1b) 0-0-1-1-2-2-3-0

What problems occur in a pipelined CPU architecture when conditional branches are encountered? Name and describe ways in which the effects of conditional branches can be reduced or eliminated.

Consider an n-channel MOSFET with tox = 4.5 nm, n = 445 cm2 /V·s, Vt = 0.55 V, and W/L = 15. What is the value of k’n ? (6 points) Identify the region of operation and find the drain current in the following four cases. (5 points each) Use r = 3.9 for Silicon.
a. vGS = 2.0 V and vDS = 2.5 V b. vGS = 2.5 V and vDS = 1.5 V c. vGS = 2.0 V and vDS = 1 V d. vGS = vDS = 2.0 V

What is the connection between Electronic
Circuits and modern digital communication
systems?

Problem 5. (10 pts) In a differential amplifier, the non-inverting input is 3 cos (600t
+ 45◦) mV and the inverting input is 4cos (600t - 45◦) mV. The output is vo = 3cos (600t + 45◦) + 4.004cos (600t - 45◦) V. The CMRR is dB

Give a brief description of the diaphragm box, how it works and its common types.

Problem 3: The carrier c(t) = 100cos(2p fct) is frequency modulated by the signal m(t) =
5cos(20000pt) , where fc = 108 Hz. The peak frequency deviation is 20 kHz. Determine the
amplitude and frequency of all the signal components that have a power level of at least 10% of
the power of the un-modulated carrier component.
Hint: The wide-band FM has frequency components, fc, fc+ fm, fc? fm, fc+2 fm, fc?2 fm,
and so on. The amplitude of the frequency components fc+n fm and fc?n fm is AcJn(b) where the
symbols have common meaning. You need to the find the frequency and amplitude of the components
that have at least 10% of the power of the un-modulated carrier (i.e., the signal components
that have at least 500 Watt power).

A single- phase full- wave rectifier is used to control the speed of a 5- hp, 110- V, 1200- rpm, separately- excited dc motor. The converter is connected to a single- phase, 120- V, 60- Hz supply. The motor has a winding resistance of 0.4ohms and an inductance of 5 mH, and a voltage constant K=0.09V/rpm.

a. During the motoring operation, the motor runs at 1000 rpm and receives an armature current of 30 A. Determine the corresponding firing angle and the power to the motor.

b. The polarity of the emf is reversed to get a regenerative action. Determine the firing angle required to keep the motor speed at 1000 rpm with an armature current of 30A. What is the power fed back to the supply under these conditions?

1. Design a bandpass filter to meet the following specificatoins: lower stopband edge = 0.3π upper stopband edge = 0.6π lower passband edge = 0.4π upper passband edge = 0.5π Rp = 0.5 dB, As = 50 dB Use a sampling frequency of 1000 Hz. You may use MATLAB and the fir1 commmand to implement. It is advisable to check the MathWorks site for help on using these commands. It is advisable to check if the commands use the ripple in dB or in absolute units and you may use MATLAB commands to convert if needed. Note, since you must title and label axes, the default plot from freqz is not sufficient but you may use freqz to generate the frequency response and plot that data using the plot command ( and a few others to convert to dB ). a. Use one of the fixed windows that meets specification. Plot the magnitude ( in dB ) and phase response. Note: the order of the filter can be computed according to the formulas on page 20 of file ADSP-10 and the example on page 23, for example for the Hamming window : 4w = 6.6π/L where L = filter order and 4w is the transition band width. ( 1 point ) b. Use a Kaiser window to meet the same specification. Plot the magnitude ( in dB ) and phase response. You may use MATLAB commands to estimate the order of the filter and implement using the fir1 command. ( 1 point ) c. Verify that both part a. and part b. meet the Rp and As specifications.

PLEASE SLOVE USING MATLAB

A proposed re-lamping project includes 200, 2 lamp fixtures. The existing lamps are standard 40 W fluorescent bulbs with a lifespan of 20,000 hours that cost $1.25 each. The proposed replacement lamps would be high efficiency devices that give the same light output for only 34 W input with a life of 22,000 hours. These lamps cost $2.50 each. The fixtures are on 250 days for 12 hours a day during a year. Electricity costs are 0.12 $/kWh and 180 $/kW-year for energy and demand respectively.

a)Compute the annual energy savings (kWh)

b) compute the power demand reduction in kW per year