Electrical Engineering Answers

1. An RF amplif er has an S/N ratio of 8 at the input and an S/N ratio of 6 at the output. What are the noise factor and noise figure? 

2. A receiver with a 75-Ω input resistance operates at a temperature of 31°C. The received signal is at 89 MHz with a bandwidth of 6 MHz. The received signal voltage of 8.3 μV is applied to an amplifier with a noise figure of 2.8 dB. Find (a) the input noise power, (b) the input signal power, (c) S/N, in decibels, (d) the noise factor and S/N of the amplifier, and (e) the noise temperature of the amplifier.

1 The signal input power to a receiver is 6.2 nW. The noise power is 1.8 nW. What is the S/N ratio? What is the S/N ratio in decibels? 

2. The circuits in a superheterodyne receiver have the following gains: RF amplifier, 8 dB; mixer, -2.5 dB; IF amplifier, 80 dB; demodulator, -0.8 dB; audio amplifier, 23 dB. What is the total gain?

A power amplifier has an input of 90 mV across 10 kV. The output is 7.8 V across an 8-V speaker. What is the power gain, in decibels?

1.Simplify the following Boolean functions using four-variable map: F (A, B, C, D) = Σ (4, 6, 7, 15)

2.Simplify the following Boolean functions using four-variable map: F (w, x, y, z) = Σ (1, 4, 5, 6, 12, 14, 15) 

3.Simplify the following Boolean expressions using four-variable map: a. F = w’z + xz + x’y + wx’z

Country’s Government has approved a relocation plan for a section of its population to inhabit a 3-island portion. Design a hypothetical Telecommunication network(Fixed and mobility consideration) for both internal and external communication.

Consider the following

1. Islands location is 5000km from the main land

2. Islands are equidistant from one another

3. Accessibility by water transport

4. Government very resourceful – enough money

5. A lot of economic activity on the Islands (billions of dollars annually)

6. 1.5 million population with 80% adults

7. 120-kilometre bridge links the three islands

3. The population of growth of a certain colony of mosquitoes follows the uninhabited growth

equation. If there are 1500 mosquitoes initally, and there are 2500 muoquitoes after 24 hours, what is the size of the mosquito population after 3 days?

A circuit has an impedance 𝑍 = 5(1 + 𝑗𝑤)(3 + 𝑗𝑤) 𝑗𝑤(2 + 𝑗𝑤) Ω Find the resistance, reactance, conductance and susceptance at w = 1 rad/s. If the time domain voltage applied to the circuit is 20 cos t V, find the steady-state current.  

convert the following expression into a standard sop form: a + b(ac + (b + c!)d)