GATE Electronics|Electrical

Explain maximum power transfer theorem in detail? Ans.   The maximum power transfer theorem states that in order to obtain maximum power from a source having a finite internal resistance, the resistance of the load must equal the resistance of the source as viewed from its output terminals across the load resistor. The theorem results in maximum power transfer and not maximum efficiency. If the resistance of the load is greater than the resistance of the source, then efficiency is higher since a higher percentage of the source power is transferred to the load, but the magnitude of the load power is lower in this case as the total circuit resistance goes up.

State space analysis is applicable even if the initial conditions are _ a) Zero b) Non-zero c) Equal d) Not equal Answer: b Explanation: State space analysis is the analysis different from the transfer function approach as it has state variables and state vectors used for the analysis and can be used even if initial conditions are non-zero. GATE ELECTRONICS 2020 https://t.me/GateElectronics

Which mechanism in control engineering implies an ability to measure the state by taking measurements at output? a) Controllability b) Observability c) Differentiability d) Adaptability Answer: b Explanation: Observability and controllability are the two methods to check the output response characteristics and observability in control engineering implies an ability to measure the state by taking measurements at output. GATE ELECTRONICS 2020 https://t.me/GateElectronics

Q. The closed system has higher ____ than open loop control system, this implies increased speed of response. a) Gain b) Bandwidth c) Frequency d) Speed Answer: b Explanation: As transient response of the system is improved by the use of feedback and it causes the settling time to reduce and closed loop system has higher bandwidth than open loop systems and this implies increase in speed of response. GATE ELECTRONICS 2020 https://t.me/GateElectronics

What are Path loss and Flicker noise? Do they depend on frequency? Ans. Path loss is the attenuation of an electromagnetic wave as it propagates through space. It is proportional to square of frequency. Path loss is a major component in the analysis and design of the link budget of a telecommunication system.  “Flicker Noise is the 1/f noise that exhibits an inverse frequency power density curve. It occurs in almost all electronic devices and are usually related to the flow of direct current. GATE ELECTRONICS 2020 https://t.me/GateElectronics

What is the difference between Mealy and Moore state machine? Explain it. Ans. In Mealy state machine we can calculate the next state and output both from the input and present state. But in the Moore state machine we can calculate only next state but not output from the input and state. The output is issued from the input and state. The output is issued according to next state.

What are hardware interrupts present in 8085 microprocessor? Ans. TRAP, RST 7.5, RST 6.5, RST 5.5 and INTR.

What is meant by weighted coded? Ans. The codes which have specific weight associated with each bit are known as weighted codes. Weighted Codes:-The weighted codes are those that obey the position weighting principle,which states that the position of each number represent a specific weight. In these codes each decimal digit is represented by a group of four bits. In weighted codes, each digit is assigned a specific weight according to its position. For example, in 8421/BCD code, 1001 the weights of 1, 1, 0, 1 (from left to right) are 8, 4, 2 and 1 respectively. Examples are 8421, 5421 codes. GATE ELECTRONICS 2020 https://t.me/GateElectronics

(Q.1-Q.3) An AM signal is represented by x(t) = (20 + 4sin(500πt)) cos(2πt x 105)V. 1. The modulation index is a) 20 b) 4 c) 0.2 d) 10 Answer: c Explanation: 20 + 4sin(500πt) = 20(1 + 0.2sin(500πt)), hence the modulation index is 0.2. 2. Total signal power is a) 208 W b) 204 W c) 408 W d) 416 W Answer: b Explantion: Pc = 20×20/2 or 200 W. Pt = Pc(1 + 0.2×0.2/4) or 204 W. 3. Total sideband power is a) 4 W b) 8 W c) 16 W d) 2 W Answer: a Explanation: Pt – Pc = 204 – 200 = 4W. GATE ELECTRONICS 2020 https://t.me/GateElectronics