An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate of flow of electric charge through a surface or into a control volume. The moving particles are called charge carriers, which may be one of several types of particles, depending on the conductor. In electric circuits the charge carriers are often electrons moving through a wire. In semiconductors they can be electrons or holes. In a electrolyte the charge carriers are ions, while in plasma, an ionized gas, they are ions and electrons.The SI unit of electric current is the ampere, or amp, which is the flow of electric charge across a surface at the rate of one coulomb per second. The ampere (symbol: A) is an SI base unit Electric current is measured using a device called an ammeter.Electric currents create magnetic fields, which are used in motors, generators, inductors, and transformers. In ordinary conductors, they cause Joule heating, which creates light in incandescent light bulbs. Time-varying currents emit electromagnetic waves, which are used in telecommunications to broadcast information.
Okay, so according to the transformer equation, VpIp = VsIs
In this question, I know I have to calculate Ip.
I think given, Vp = 9V, Vs = 120 V
Now I don't know what to use in the value of Is.
Please help!
The answer is 2.32 A.
My understanding of emf
Let us consider 2 parallel plates with charges (opp. but equal in magnitude) stored on it. When we connect both the plates from the outer side, the electrons from the lower potential (i.e., negatively charged plate) moves to the higher potential (positively charged plate)...
Options are at the top of page as a) b) c) d)
Answer may more than one.
Now since 'a' is distance from the smaller surface of cone so as we move along the axis area will increase,So current charge density will decrease and as we know J=sigma E,E will decrease,but V will remain constant since...
Homework Statement
The potential difference across resistance R carrying current I is V = IR . Now if the potential difference is measured via voltmeter of resistance r , the reading on voltmeter is V' . Prove that V' = Ir/(R+r) . For what value of r does the voltmeter measure true value...
Homework Statement
Figure shows a potentiometer circuit for comparison of two resistances , the balance point with standard resistor R = 10 ohm , is found to be 58.3 , while that with unknown resistance X is 68.5 cm , determine the value of X .
b) what might you do if you failed to find the...
Homework Statement :
[/B]
If the length of the filament of a heater is reduced by 10%, the power of the heater:
Options are-
a) increases by about 9%.
b) increases by about 11%.
c) increases by about 19%.
d) decreases by about 10%.
Homework Equations :
P[/B]=I2R
Or
P=V2/R
Where P=power...
Homework Statement
We have to measure emf of a battery. We have to voltmeters. Each of them when connected alone across the battery, they read V1 = 0.9V and V2 = 0.6V and when both of them are connected to the battery simultaneously, they both read V3 = 0.45V . What is the emf of battery...
Homework Statement
Pic A, what's the I2?
Pic B, what's the current across a-b ?
Homework Equations
V = I*R
Voltage in series is different, the current is the same
Current in parallel is different, the voltage is the same
The Attempt at a Solution
from Pic A, I found that I1 = 1A, I3 = 1A...
The definitions of electromotive force of a cell that i have read include:
1.When no current is drawn from a cell,i.e., when the cell is in open circuit, then potential difference between the terminals of the cell is its electromotive force.
2.The electromotive force of a cell is defined as...
Hello,
I'm trying to make a project and I have a trouble. The project is 'online monitoring of machine'. I will show ON if machine works and OFF if machine does not work. And the rule is: I can not effect machine by my circuit. So it looks so simple. I bought SCT-013 non-invasive current sensor...
Homework Statement
Homework Equations
How to find error in resistance ?
The Attempt at a Solution
I found out the resistance without error.
But What is the way to figure out an error of an instrument ?
i know that all conductors are equipotential,then how are charges flowing in a conductor?and at times in we say that charges won't flow since two points are equipotential(like in wheat stone bridge we say that charge won't flow across the capacitor/resistor since the ends of the 5th...
Can someone explain me,why Wheatstone bridge is most sensitive when all four resistances say A,B,C and D are equal?as far as i know condition for Wheatstone Bridge is A/B=C/D.