Physics

1. Write your understanding on resonance condition for an RLC circuit. What are the reactance’s for a capacitor and an inductor in RLC circuit? 2. Determine the resonance frequency and bandwidth from the graph. Find the Q-factor also. A resonance curve for the parallel LC circuit 1 0.9 0.8 0.7 0.6 Voltage 0.5 0.4 0.3 0.2 0.1 8 0 0 4 7 10 Frequency: Bandwidth: Q-Factor: Frequency KHz KHz

Physics, Science / By

EXPERT ANSWER The resonance is the condition where we get maximum value of the amplitude and in RLC circuit when the impedance is minimum at a particular frequency then we get maximum amplitude and that frequency is known as resonant frequency. Bandwidth is the difference of half part frequencies and can be obtained from the …

1. Write your understanding on resonance condition for an RLC circuit. What are the reactance’s for a capacitor and an inductor in RLC circuit? 2. Determine the resonance frequency and bandwidth from the graph. Find the Q-factor also. A resonance curve for the parallel LC circuit 1 0.9 0.8 0.7 0.6 Voltage 0.5 0.4 0.3 0.2 0.1 8 0 0 4 7 10 Frequency: Bandwidth: Q-Factor: Frequency KHz KHz Read More Β»

A lift with its occupants has a mass of 5000 kg . Calculate the tension in the elevator cable if it is: a) accelerated upward by 1.5 m/s 2 ; b) decelerated upward by 1.5 m/s2; c) accelerated downward by 1.5 m/s 2 ; d) decelerated downward by 1.5 m/s 2 . The spring of a cork gun has a spring constant of 20 N/m . A cork is shot horizontally from 10 m above the ground using this gun. How far the cork will travel before it hits the ground; ignore the air resistance in the calculation.

Physics, Science / By

EXPERT ANSWER

1. In a water to air heat exchanger, it is important to place fins on the air side because a. The air side heat transfer coefficient is so much lower than on the water side. b. It reduces drag in high speed flows c. The air side heat transfer coefficient is higher than that of the water side d. It affects good mixing of the gas and this promotes good heat transfer 2. In a heat exchanger, when is the heat transfer maximum? a. T(cold inlet) = T(hot inlet) b. T(cold inlet) = T(cold outlet) c. T(cold outlet) = T(hot outlet) d. The equipment is new 3. Which of the following a measure of the performance of an evaporator? a. Heat transfer rate b. Steam economy c. Heat transfer coefficient d. Heating surface area 4. Which of the following is most likely the effect of lowering the feed temperature in an evaporator? a. Decreased heating area requirement b. Reduced steam consumption c. Reduced steam economy d. Increased capacity 5. A greater wall thickness of the packing material (i.e. Raschig Rings) will result a / an a. Decreased superficial velocity b. Greater free space c. Increased surface area d. Increased pressure drop 6. Which of the following is TRUE as regards to gas absorption? a. The operating line is always straight b. The operating line is below the equilibrium line c. The operating line represents a heat balance d. For efficient mass transfer, the resistance in the liquid film should be low.

Physics, Science / By

EXPERT ANSWER 1)a) option is the right answer. Fins are used to increase heat transfer where heat transfer coefficient is low by increasing effective heat transfer area. This statement supports first option is the best choice. 2) d) option is correct heat transfer rate Q is directly proportional to heat transfer coefficient(U), effective area(A) and …

1. In a water to air heat exchanger, it is important to place fins on the air side because a. The air side heat transfer coefficient is so much lower than on the water side. b. It reduces drag in high speed flows c. The air side heat transfer coefficient is higher than that of the water side d. It affects good mixing of the gas and this promotes good heat transfer 2. In a heat exchanger, when is the heat transfer maximum? a. T(cold inlet) = T(hot inlet) b. T(cold inlet) = T(cold outlet) c. T(cold outlet) = T(hot outlet) d. The equipment is new 3. Which of the following a measure of the performance of an evaporator? a. Heat transfer rate b. Steam economy c. Heat transfer coefficient d. Heating surface area 4. Which of the following is most likely the effect of lowering the feed temperature in an evaporator? a. Decreased heating area requirement b. Reduced steam consumption c. Reduced steam economy d. Increased capacity 5. A greater wall thickness of the packing material (i.e. Raschig Rings) will result a / an a. Decreased superficial velocity b. Greater free space c. Increased surface area d. Increased pressure drop 6. Which of the following is TRUE as regards to gas absorption? a. The operating line is always straight b. The operating line is below the equilibrium line c. The operating line represents a heat balance d. For efficient mass transfer, the resistance in the liquid film should be low. Read More Β»

6. A body is dropped from a height of 300ft with an initial velocity of 30 ft /sec. Assuming no air resistance, (a) find an expression for the velocity of the body at any time t; (b) find the time r(1u1red for the body to hit the ground. 7. A ball is propelled straight up with an initial velocity of 250 ft/sec in a vacuum with no air resistance. How high will it go ?

Physics, Science / By

EXPERT ANSWER 6) a) V = U + g*t where U – initial velocity b) h = ut + .5gt^2 300 = 30t + .5* 32.17*t^2 t = 3.49 sec 7) h = u^2 /2g = 250^2/(2*32.17) = 971.4 ft