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Determine the member forces and the reaction forces for the truss structure shown in figure with proper assumptions
A member ABCD is subjected to point loads P1, P2, P3 and P4 as shown in Fig. Calculate the force P3,necessary for equilibrium if P1 = 120 kN, P2 = 220 kN and P4 = 160 kN. Determine also the net change in length of the member. Take E = 200 GN/m2.
Direct stresses of 120 N / mm ^{2}N/mm2 (tension) and 90 N / mm ^{2}N/mm2 (compression) are applied at a particular point in an elastic material on two mutually perpendicular planes. The principal stress in the material is limited to 100 N / mm ^{2}N/mm2 (tension). Calculate the allowable value of shear stress at the point on the given planes. Determine also the value of the other principal stress and the maximum value of shear stress at the point. Verify your answer using Mohr’s circle.
1. What is the open-circuit noise voltage across a 100-kΩ resistor over the frequency range of direct current to 20 kHz at room temperature (25°C)?
2. The bandwidth of a receiver with a 75-Ω input resistance is 6 MHz. The
temperature is 29°C. What is the input thermal noise voltage?
3. What is the average noise power of a device operating at a temperature of 90°F with a bandwidth of 30 kHz?
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
Simplify the following Boolean functions using three-variable map:
F (x, y, z) = Σ (0, 1, 5, 7)
At 200C, there is a gap d = 0.2 mm between the lower end
of the bronze bar and the rigid slab supported by two
steel bars as shown. Neglecting the mass of the slab,
determine the stress in each rod when the temperature
assembly is increased to 1000C.
