• In unit operations their is only physical change is occur but no chemical change take place or we can say no chemical reaction take place.
• Evaporation, Distillation, Liquid liquid extraction, Drying, Size reduction, Crystallization are the example of unit operations.
• In these operations thier is only physical change take place like phase will be change or two or more substances are separated each other or particle size will reduce.
• Unit operations are processes related to physical changes of the materials involved:
  • Mixing (Solid-Solid, Solid-Liquid, Solid-Gas, Liquid-Liquid, Liquid-Gas, Gas-Gas)
  • Separating (Sieving, Filtration, Distillation, Fractional crystallization, Fractional freezing, Centrifugation)
  • Heating / Cooling of materials
  • Transporting (Solids, Granulates, Liquids, Slurries, Pastes, Gases)
  • Measuring (Weighing, Volumetrizing, Counting)

• Compressive strength test on bricks are meted out to see the load carrying capability of bricks under compression. This test is meted out with the assistance of compression testing machine.
• Bricks are usually used for construction of load bearing masonry walls, columns and footings. These load bearing masonry structures experiences largely the compressive loads. Thus, it’s necessary to understand the compressive strength of bricks to envision for its suitableness for construction.
• Apparatus, sampling, procedure and calculations to see the compressive strength of bricks are mentioned below.
• Minimum compressive strength of brick varies for different grades of bricks
  • For Common building brick = 35kg/sq. cm
  • For second class brick = 70kg/sq. cm
  • For First class brick = 105kg/sq. cm
  • For AA class brick = not less than 140kg/sq. cm

• It relies on the height of the building.
• In the event that the structure is G + 3 the steel utilization is around 2.5 kg per sq.ft.
• In the event that the structure is tower of 15 storeys the steel utilization can be as high as 6 kg for every sq.ft.
• For towers which are 25 storeys high steel utilization is 7.5kg per sq.ft.

• This is the method to calculate number of bricks and sand and cement on 10 ft height 10 ft length 4-inch wall (building inner wall) with 1:4 ratio.
• Since you said it is an inner wall, i am assuming it as partition wall without any opening in case 1.

• 1. For 10′x10′x4″ wall you need
  2. Bricks = 476 No’s
  3. Cement = 57 kg (125.66 pound)
  4. sand = 0.237 m^3 (8.3695 cft)

• Excessive curing is bad for the walls because it causes fungi formation on the bricks which may weaken the walls.

• Curing is the process of controlling the rate and extent of moisture loss from concrete to ensure an uninterrupted hydration of Portland cement after concrete has been placed and finished in its final position.
• Curing also ensures to maintain an adequate temperature of concrete in its early stages, as this directly affects the rate of hydration of cement and eventually the strength gain of concrete or mortars.
• Curing of concrete must begin as soon as possible after placement & finishing and must continue for a reasonable period of time as per the relevant standards, for the concrete to achieve its desired strength and durability. Uniform temperature should also be maintained throughout the concrete depth to avoid thermal shrinkage cracks. Also protective measures to control moisture loss from the concrete surface are essential to prevent plastic shrinkage cracks.
• In a nut shell, curing process is designed primarily to keep the concrete moist by controlling the loss of moisture from the body of concrete, during the given period in which it gains strength.

• First of all, we make the concrete cube at some mix proposition as M15, M20.
• Then after one day the curing on concrete cube at 7days or 28days and we find out the compressive strength of concrete

• Properly sized and located reinforcing will keep cracks reasonably tight and serviceable, if they occur, but will not prevent them. Furthermore, the great majority of reinforced concrete designs that have been reviewed for slabs on ground do not have enough reinforcing to actually increase the slab’s load-carrying capacity above that of an unreinforced slab.

• If you are using bamboo in place of steel than you can use mud in place of concrete.
• IS Code:
  • IS: 456 – Code of observe for plain and concrete.
  • IS: 383 – Specifications for fine & coarse mixture from natural sources for concrete.
  • IS: 6909 – Specifications for SSC (super sulphated cement)

• Body wall of the weir
• Upstream solid apron
• Apron on downstream side
• Curtain walls on Upstream & Downstream
• Talus on Upstream & Downstream
• Shutter on the crest of weir

• It is a wall which is constructed to raise the water level on u/s
• To raise water level on u/s
• To resist water pressure
• To resist uplift pressure

• Protect weir from erosive forces during floods
• Length of apron depends upon discharge in river and length of weir
• To prevent any leakage in the sub soil

• To reduce the kinetic energy of water
• Length depends upon height of fall of water nature of soil discharge in river
• Apron is extended up to the point where there is no scope for erosion
• It Should have sufficient width to resist uplift pressure

• Upstream curtain wall
  • To reduce uplift pressure
  • Length depends on nature of sub soil
  • To increase length of the creep
  • To reduce exit gradient

• Downstream curtain wall
  • Protect downstream flow from uplift pressure.
  • To resist kinetic energy of water increase length of creep

• Provide on the crest It can be raised during flood To resist water pressure
  • Protect downstream flow from uplift pressure.
  • To resist kinetic energy of water increase length of creep

• The lap length including anchorage value of hooks shall be1. For flexural tension – Ld or 30d whichever is greater.2. For direct tension – 2Ld or 30d whichever is greater.
• The straight length of lapping shall not be less than 15d or 20 cm

• The hook length is commonly provided for stirrups

• Hook Length = 9D [D is Diameter of the Bar]

• Overlap Length for compression members = 40D
• Overlap Length for tension members = 50D
• [D is the Diameter of the bar]

• Yes we can connect two or more energy meters/Amp meters on one CT set. Actually current always flow in series. So put one wire from ct s1 and connect on first energy meter s1 and put one wire from s2 of first energy meter and connect on s1 of second energy meter and second energy meters s2 connect on ct’s s2.
• Then your current path become fine and there will be same rating in two energy meter which is connected.
• Like this all phase CT can be connected on energy meter and by making the phase voltage line on meter parallel.

Putting CTs in parallel

• All of the transformers (CTs) should have a similar nominal ratio, in spite of the rating of the circuits during which they’re connected.
• The secondary leads should be paralleled at the meter and not at this electrical device.
• There ought to be only 1 ground on the secondary facet of all transformers at their common purpose at the meter.
• Use fashionable current transformers with low exciting currents and, therefore, very little shunting impact once one or a lot of current transformers ar floating at no load. (Three of a lot of floating current transformers might have a control that ought to be investigated).
• The secondary circuits should be designed so the utmost potential burden on any electrical device won’t exceed its rating. The burden ought to be unbroken as low as potential as its effects are increased in direct proportion to the sq. of the overall secondary current. A Common voltage should be available for the meter. This condition is met if the circuits share a standard bus that’s ordinarily operated with closed bus ties.
• Burdens and accuracies should be fastidiously calculated. If changes are created at the meter to atone for ration and point errors, the magnitude relation and point error corrections used should represent the complete combination of transformers connected as a unit.
• The watt hour meters should be of adequate current capability to hold while not overload errors the combined currents from all the transformers to that it’s connected.
• Low-voltage, low-burden-capability current transformers don’t seem to be suited to the current application since the burden imposed on parallel secondary is also terribly high.
• Meter voltage typically is supplied with a throw-over relay to avoid loss of meter voltage within the event the conventional provide is de-energized.

• Meter rev constant means rev/ kwh.

• Then one rotation = 60×60/400 or 9kws.

• 2 rotations = 18kws.

• Time taken is 30s.

• Then the av load is 18/ 30 or 0.6 kw.

• To calculate whether this Energy Meter is slow or fast using this formula.

Slowness/Fastness=Tc−To/To X 100

• Yes,it surely does. Actually capacitor bank feeds the inductive load with a part of KVAR which it takes from the main power supply line.
• Hence it reduces the power demanded by the main line in other words the inductive lags the power factor and the capacitive loads improves it by supplying the certain amount of KVAR.
• Power is calculated for a 3 phase CCT as 1.73 x Voltage x Ampere x PF.
• When capacitor is connected in parallel the PF is improved but the actual current is proportionately, So we don’t see any power being consumed less.

• Stepper motors are DC motors that move in discrete steps. They have multiple coils that are organized in groups called “phases”. By energizing each phase in sequence, the motor will rotate, one step at a time. With a computer controlled stepping you can achieve very precise positioning and/or speed control.

• Permanent magnet motors use a static magnet (PM) within the rotor and operate the attraction or repulsion between the rotor PM and also the stator coil electromagnets.

• Hybrid stepper motors are named because they use a mixture of static magnet (PM) and variable reluctance (VR) techniques to attain most power in an exceedingly little package size.

• Variable Reluctance (VR) motors have a comprehensible iron rotor and operate supported the principle that minimum reluctance happens with minimum gap, hence the rotor points are attracted toward the mechanical device magnet poles.

• Short Transmission Line
• Medium Transmission Line
• Long Transmission Line

Short Transmission Line

• A transmission line having its length under 80 kilometer is taken into account as a short transmission line. In short transmission line capacitance is neglected due to little leak current and alternative parameters (resistance and inductance) ar lumped within the transmission line.

• Medium length transmission lines are “the transmission lines whose length is between 80 kilometer and 250 km”. The voltage transmission ability of those medium length transmission lines is around 20 kilovolt to 100 kilovolt.
• For a medium transmission line, charging current is substantial and due to the length of the line the shunt admittance plays a significant role in the calculation of the effective parameters of the line.
• The shunt admittance and series impedance are considered as a lumped parameter of the medium transmission line. The medium transmission line is shown below in the diagram.

• Many localized capacitance models have been used to make approximate line performance calculations. The following models are commonly used.
  • Nominal T model
  • Nominal ∏ (pi) model

• A power transmission line with its effective length of around 250 Kms or higher than is stated as an extended transmission line. The line constants area unit uniformly distributed over the whole length of line.

• To provide proper cooling.
• To provide proper insulation.
• And it has all the necessary important properties like high ignition tempratue.,no sludge formation, low resistance to imulsion,etc.

• A = Appearing as a first letter denotes Aluminium Conductor.
• Y = PVC Insulation or PVC Sheath depending on the position in which it appears.
• 2X = 2-X (Cross-linked Polyethylene) Insulation.
• W = Round Steel Wire Armouring.
• WW = Double Round Steel Wire Armouring.
• F = Formed Steel Wire (Strip) Armouring.
• FF = Double Formed Steel Wire (Strip) Armouring.
• C = Metallic Screening (Usually of Copper).
• CE = Metallic Screening (usually of Copper) over each individual core.
• WA = Aluminium Round Wire & Aluminium Formed Wire (Strip) Armouring.

Types	Description
AYY	AYY Aluminium Conductor, PVC Insulated, PVC Outer Sheathed.
AYWY	AYWY Aluminium Conductor, PVC Insulated, Galvanised Round Steel Wire Armoured and PVC Outer Sheathed.
AYFY	AYFY Aluminium Conductor, PVC Insulated, Galvanised Flat Steel Wire (Strip) Armoured and PVC Outer Sheathed Cable.
AYCY	AYCY Aluminium Conductor, PVC Insulated, Metallic Screened and PVC Outer Sheathed.
A2XCY	A2XCY Aluminium Conductor, XLPE Insulated, Metallic Screened and PVC Outer Sheathed.
AYCEFY	AYCEFY Aluminium Conductor, PVC Insulated, individual core metallic screened, Flat steel Wire (strip) Armoured and PVC Outer Sheathed.
A2XCEFY	A2XCEFY Aluminium Conductor, XLPE Insulated, individual cores metallic screened, Flat Steel Wire (Strip) Armoured and PVC Outer Sheathed.

• AYFY Means Alluminum PVC Insulated Flat strip armour and PVC outer sheeth cable .
• AYFY stands for,
  • A-Aluminum
  • Y-inner sheath for insulation
  • F- Flat armored (There is one more thing WOUND ARMOURED).
  • Y-outer sheath of insulation.

Here we provide coordination chart link for required rating and model of MCCB.

• Molded case circuit breakers are a type of electrical protection device that is generally used for a wide range of voltages, and frequencies of both 50 Hz and 60 Hz.
• The main distinctions between molded-case and miniature circuit breaker are that the MCCB can have current ratings of up to 2,500 amperes, and its trip settings are usually adjustable.

• Currents above the rated value that last longer than what is normal for the application.

• During a fault such as a short circuit or line fault, there are very high currents that must be interrupted directly.

• This is a less common function of circuit breakers, but they can be used for that purpose if there isn’t a suitable manual switch.