1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Tems11 [23]
2 years ago
7

In alternating current, how often does the current alternate between negatively and postively?

Engineering
2 answers:
Serggg [28]2 years ago
4 0
In an alternating current (AC) circuit the two poles alternate between negative and positive and the direction of the current (electron flow) reverses periodically.
strojnjashka [21]2 years ago
4 0
1/60th of a second each way back and forth
You might be interested in
An 800-kg drag racer accelerates from rest to 390 km/hr in 5.8 s. What is the net impulse applied to the racer in the first 5.8
marissa [1.9K]

Answer:

Impulse =14937.9 N

tangential force =14937.9 N

Explanation:

Given that

Mass of car m= 800 kg

initial velocity u=0

Final velocity v=390 km/hr

Final velocity v=108.3 m/s

So change in linear momentum P= m x v

           P= 800 x 108.3

 P=86640 kg.m/s

We know that impulse force F= P/t

So F= 86640/5.8 N

F=14937.9 N

Impulse force F= 14937.9 N

We know that

v=u + at

108.3 = 0 + a x 5.8

a=18.66\ m/s^2

So tangential force F= m x a

F=18.66 x 800

F=14937.9 N

6 0
3 years ago
An insulated piston-cylinder device contains 0.15 of saturated refrigerant-134a vapor at 0.8 MPa pressure. The refrigerant is no
Stells [14]

Answer:

Assumption:

1. The kinetic and potential energy changes are negligible

2. The cylinder is well insulated and thus heat transfer is negligible.

3. The thermal energy stored in the cylinder itself is negligible.

4. The process is stated to be reversible

Analysis:

a. This is reversible adiabatic(i.e isentropic) process and thus s_{1} =s_{2}

From the refrigerant table A11-A13

P_{1} =0.8MPa   \left \{ {{ {{v_{1}=v_{g}  @0.8MPa =0.025645 m^{3/}/kg } } \atop { {{u_{1}=u_{g}  @0.8MPa =246.82 kJ/kg } -   also  {{s_{1}=s_{g}  @0.8MPa =0.91853 kJ/kgK } } \right.

sat vapor

m=\frac{V}{v_{1} } =\frac{0.15}{0.025645} =5.8491 kg\\and \\\\P_{2} =0.2MPa  \left \{ {{x_{2} =\frac{s_{2} -s_{f} }{s_{fg }}=\frac{0.91853-0.15449}{0.78339}   = 0.9753 \atop {u_{2} =u_{f} +x_{2} }(u_{fg}) =  38.26+0.9753(186.25)= 38.26+181.65 =219.9kJ/kg \right. \\s_{1} = s_{2}

T_{2} =T_{sat @ 0.2MPa} = -10.09^{o}  C

b.) We take the content of the cylinder as the sysytem.

This is a closed system since no mass leaves or enters.

Hence, the energy balance for adiabatic closed system can be expressed as:

E_{in} - E_{out}  =ΔE

w_{b, out}  =ΔU

w_{b, out} =m([tex]u_{1} -u_{2)

w_{b, out}  = workdone during the isentropic process

=5.8491(246.82-219.9)

=5.8491(26.91)

=157.3993

=157.4kJ

4 0
3 years ago
2.1 What is the minimum number of pins required for a so-called dual-op-amp IC package, one containing two op amps? What is the
cupoosta [38]

Answer:

8 for dual-op-amp package, and 14 for quad-op-amp

Explanation;

This is because every op-amp has 2 input terminal 4 pns

So one output terminal that is 2 pins which are required for power

and the same for a minumum number of pins required by quad op amp which is 14

5 0
3 years ago
Identify three operational controls and explain<br> how to use them?
ladessa [460]

Answer:

5.1 Personnel Security. ...

5.2 Physical and Environmental Protection. ...

5.3 Production, Input and Output Controls. ...

5.4 Contingency Planning and Disaster Recovery. ...

5.5 System Configuration Management Controls. ...

5.6 Data Integrity / Validation Controls. ...

5.7 Documentation. ...

5.8 Security Awareness and Training.

8 0
3 years ago
Shane's 100-watt radio draws 7 amps of current on a 120-volt circuit. What is the resistance in the radio?
lawyer [7]

Answer:

Resistance, R = 2.04 Ohms.

Explanation:

Given the following data;

Current = 7 amps

Circuit voltage = 120 Volts

Power = 100 Watts

To find the resistance;

First of all, we would calculate the potential difference (voltage level) used by the radio.

Power = current * voltage

100 = 7 * voltage

Voltage = 100/7

Voltage = 14.29 Volts

Next, we solve for the resistance of the radio;

Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.

Mathematically, Ohm's law is given by the formula;

V = IR

Where;

V represents voltage measured in voltage.

I represents current measured in amperes.

R represents resistance measured in ohms.

Substituting into the formula, we have;

14.29 = 7*R

R = \frac {14.29}{7}

Resistance, R = 2.04 Ohms.

7 0
2 years ago
Other questions:
  • An ideal gas undergoes two processes: one frictionless and the other not. In both the cases, the gas is initially at 200 ℉ and 1
    7·2 answers
  • During an office party, an office worker claims that a can of cold beer on his table warmed up to 20oC by picking up energy from
    13·1 answer
  • A harmonic oscillator with spring constant, k, and mass, m, loses 3 quanta of energy, leading to the emission of a photon.
    13·1 answer
  • What must you do if hauling a load of material which could fall or blow onto the roadway?
    14·1 answer
  • Which one of the following is a list of devices from least efficient to most efficient
    9·1 answer
  • Show that -40 F is approximately equal to -40 C.
    12·1 answer
  • A single phase molor is located
    14·1 answer
  • A coil having a resistance of 10 ohms and an inductance of 4 H is switched across a 20W dc source. Calculate (a) time required b
    9·1 answer
  • In an RL parallel circuit, VT = 240 V, R = 330 Ω, and XL = 420 Ω. What is the Apparent Power (VA)?
    9·1 answer
  • Outline how effective brainstorming should be set up so that it does not go off-track or alienate anyone.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!