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3 years ago

What is referred to as "Pyroelectric" materials?

Engineering

1 answer:

aliina [53]3 years ago

5 0

Answer and Explanation:

Pyroelectric material

Pyroelectric materials have special property of generating potential difference (although it is very less ) when these material are treated with heat or when celled down.

The potential difference generated is for very less time

The generation of potential difference is due to change in position of atoms after heating or cooling.

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Write a grammar for a language whose sentences start with an even and non-zero number of x’s, end with an odd number of z’s, and

sveta [45]

Answer:

GRAMMAR

S -> AB

A -> xxAyy | xxyy

B -> yyBzz | yz

EXPLANATION

A is for even number of x's followed by that number of y's

B is for odd number of y's followed by that number of z's

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3 years ago

System grounding on a power system means electrically connecting the __?__ of every wye-connected transformer or generator to ea

irinina [24]

Answer: Neutrals

Explanation: System grounding on a power system is a term used to describe the entire processes involved when a neutral is used as the conductor to connect to the solid earth. This ensures that power is generated. This is usually done using either an inductor, an impendance or a resistor. It is very important and necessary to carry out a proper grounding of a power system in order to ensure the safety of the equipment and the personnel etc

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3 years ago

The minimum recommended standards for the operating system, processor, primary memory (RAM), and storage capacity for certain so

nlexa [21]

Answer:System requirements

Explanation:

its right.

8 0

2 years ago

Read 2 more answers

Ultimate tensile strength is: (a) The stress at 0.2% strain (b) The stress at the onset of plastic deformation (c) The stress at

MissTica

Answer:

By definition the ultimate tensile strength is the maximum stress in the stress-strain deformation. The stress at 0.2% strain, the stress at the onset of plastic deformation, the stress at the end of the elastic deformation and the stress at the fracture correspond, by definition, to other points of the stress-strain curve.

Explanation:

4 0

3 years ago

A heat pump with an ideal compressor operates between 0.2 MPa and 1 MPa. Refrigerant R134a flows through the system at a rate of

solmaris [256]

Answer:

The mass flow rate of refrigerant is 0.352 kg/s

Explanation:

Considering the cycle of an ideal heat pump, provided in the attachment, we first find enthalpy at state B and D. For that purpose, we use property tables of refrigerant R134a:

At State A:

From table, we see the enthalpy and entropy value of saturated vapor at 0.2 MPa. Therefore:

ha = 244.5 KJ/kg

Sa = 0.93788 KJ/kg.k

At State B:

Since, the process from state A to B is isentropic. Therefore,

Sb = Sa = 0.93788 KJ/Kg

From table, we see the enthalpy value of super heated vapor at 1 MPa and Sb. Therefore:

hb = 256.85 KJ/kg (By interpolation)

At State C:

From table, we see the enthalpy and entropy value of saturated liquid at 1 MPa. Therefore:

hc = 107.34 KJ/kg

Now, from the diagram it is very clear that:

Heat Loss = m(hb = hc)

m = (Heat Loss)/(hb - hc)

where,

m = mass flow rate = ?

Heat Loss = (180,000 Btu/hr)(1.05506 KJ/1 Btu)(1 hr/3600 sec)

Heat Loss = 52.753 KW

Therefore,

m = (52.753 KJ/s)/(256.85 KJ/kg - 107.34 KJ/kg)

m = 0.352 kg/s

5 0

3 years ago