Is Ohm s law difficult, Ohm s law is suitable for

It's not difficult Ohm's law is of two kinds:

1.Ohm's law for partial circuits, also known as Ohm's law for external circuits, is i=u r u=r*i r=u i

i=current u=voltage.

r=resistance 2Ohm's law for all circuits, ie.

u (the electromotive force of the power supply.)

Voltage + current of the external circuit * internal resistance of the power supply.

The voltage of the external circuit = the equivalent resistance of the external circuit. Current.

Ohm's law is divided into Ohm's law i=u r for full circuits and Ohm's law i=e (r+r) for partial circuits, which is applicable to linear circuits (including DC circuits, AC circuits, pure resistance circuits, and circuits containing capacitive reactance), but not to nonlinear circuits.

Ohm's law for all circuits.

The current of the closed circuit is directly proportional to the electromotive force of the power supply, and inversely proportional to the sum of the resistances of the internal and external circuits. The formula is i=e (r+r), i represents the current in the circuit, e represents the electromotive force, r represents the total external resistance, and r represents the internal resistance of the battery. The commonly used variant is e=i(r+r);e=u-out+u-in;U Outer = E-IR.

Ohm's law for partial circuits.

Ohm's law for some circuits is Ohm's law that I learned in junior high school, and the content is expressed as: the current in the conductor is proportional to the voltage u at both ends of the conductor and inversely proportional to the resistance r of the conductor. It is expressed by the formula: i=u r.

Comparison of the two.

Similarities. The similarities between the two: r in the two expressions generally refers to a pure resistance (linear resistance), both of which can be applied to both DC and AC circuits.

Differences. 1) Ohm's law for some circuits does not involve power supply, while Ohm's law for closed circuits is applied to closed circuits composed of internal and external circuits, and there must be a power supply (electromotive force).

2) Ohm's law for partial circuits is often used to calculate the relationship between resistance, current and voltage of a component in a circuit, while Ohm's law for closed circuits focuses on the relationship between resistance, current and electromotive force of the entire closed circuit.

Now, Ohm's law is a simple law of electricity in classical physics, but it was not until 1821 that the thermoelectric cell and the electric current magnetic effect were discovered in 1826, after the discovery of electric currents and stacks in 1800. At that time, the concepts of resistance and voltage did not exist, and there was no highly sensitive galvanometer to determine the intensity value of the current. The achievement of an unknown law, no matter how concise and understandable it seems today, requires painstaking efforts and courageous exploration by scientists.

Ohm's law is discovered by analogy. Ohm considers the phenomenon of electric current to be similar to the phenomenon of heat: the heat flow in the thermal rod is equivalent to the current in the wire, and the temperature between the two points in the thermal rod is equivalent to the driving force between the two ends in the wire.

If the intensity of the heat flow between the two points in the thermal rod is proportional to the temperature difference between the two points, then the current intensity should also be proportional to the driving force. However, in any case, an analogy is nothing more than a mental activity, and its conclusions are to be tested by experiments.

When ohms experimented with voltaic batteries or thermoelectric batteries, they encountered difficulties in inaccurate measurements. He turned to design a torsion scale using the magnetic effect of electric current. After a large number of experiments, it is found that the calculated values are basically consistent with the experimental values.

Ohm officially published the law in "Determination of the Law of Conductivity of Metals": the current intensity is proportional to the length of the wire. In 1827, he made a mathematical treatment in "Mathematical Research on Electrodynamic Circuits" and obtained a more complete formula:

s=r稥. where s is the current intensity of the wire, r is the conductivity, and e is the potential difference between the two ends of the wire, which is the famous Ohm's law.

Ohm was born into a locksmith's family in Erlangen and had no formal education. After his ** was published, he was criticized, but his work gradually gained attention. In 1841 the Royal Society awarded him the Copley Prize.

In 1849, at the age of 62, he was appointed a non-permanent professor at the University of Munich. In order to commemorate his contribution to mankind in the field of electricity, later generations set the unit of resistance as "ohm".

Ohm's law is a fundamental law that expresses the relationship between current, voltage (or potential), and resistance in a circuit.

1) Ohm's law for partial circuits.

The current (i) through the conductor is directly proportional to the voltage (u) across the conductor and inversely proportional to the resistance (r) of the conductor, i=u r

Transform the above equation to.

u=irr=u i(2) Ohm's law for all circuits.

The current in the closed circuit is directly proportional to the electromotive force of the power supply and inversely proportional to the sum of the load resistance and the internal resistance of the power supply in the circuit, i.e.

where i – the current flowing through the circuit in amperes (a);

e - power electromotive force, in volts (v);

r – load resistance in ohms ( ).

r – the internal resistance of the power supply, in ohms ( ).

If you want to consider the resistance of the connected wires, add the resistance value of the wires to the total resistance.

Ohm's law is simply described as follows: In the same circuit, the current through a conductor is proportional to the voltage across the conductor and inversely proportional to the resistance of the conductor. This law was proposed by the German physicist Georg Simon Ohm in his book "Determination of the Law of Conductivity of Metals" published in April 1826.

As the work on circuits progressed, the importance of Ohm's law was gradually recognized, and Ohm's reputation increased greatly. In honor of Ohm's contribution to electromagnetism, the physics community named the unit of resistance Ohm, which is represented by symbols.

Standard Formula: Note: The unit of physical quantity in the formula: i: (current) is ampere (a), u: (voltage) is in volts (v), r :(resistance) is in ohms ( ).

Part of the circuit formula: i=u r, or i=u r=p u(i=u:r).

Ohm's law is a legal formula that reflects the relationship between voltage, resistance, and current. u voltage r resistance = i current.

The unit of voltage v

The unit of current is a

The unit of resistance

Over the years, under the guidance of Ohm's law, countless inventions have been born, it can be said that without this law there would be no circuit design, let us keep in mind the great achievements of Ohm's law and move on!

Ohm's law states that the current passing through a conductor in a closed circuit is directly proportional to the voltage across the conductor and inversely proportional to the resistance of the conductor.

Ohm's law states that the magnitude of the current through a conductor is proportional to the voltage across the conductor and inversely proportional to the resistance.

Ohm's law is to say that the voltage at both ends of a conductor is directly proportional to the current, and the current is inversely proportional to the resistance.

Ohm's law is of two kinds

1.Ohm's law for partial circuits, also known as Ohm's law for external circuits, is i=u r

u=r*ir=u/i

i = current. U = voltage.

r = resistance. 2.Ohm's law for all circuits, ie.

U (electromotive force of the power supply) = voltage of the external circuit + current * internal resistance of the power supply and voltage of the external circuit = equivalent resistance of the external circuit * current.

Note: The current in these two equations is the same.

3): It should be noted:

2) Ohm's law applies to metal conductors and electrolyte solutions in the usual robust state, but not to gaseous conductors and some other conductive components (tubes, thermistors). In the case of a circuit, it is only true for a length of conductor that does not contain a power supply.

Brief description: In the same circuit, the current in the conductor is directly proportional to the voltage at both ends of the conductor and inversely proportional to the resistance of the conductor, which is Ohm's law.

Ohm's law formula for partial circuits: i=u r

Wherein: i, u, r - the three quantities are the current intensity, voltage and resistance at the same time in the same part of the circuit.

The formula is derived from Ohm's law:

Parallel circuit: series circuit.

i total = i1 + i2

i total = i1 + i2

uTotal = u1 = u2

uTotal = u1 = u2

1:r total = 1:r1+1:r2

r total = r1 + r2r

i1：i2=r2：r1

u1：u2=r1：r2

r total = r1 + r2: r1r2

rtotal = r1r2r3: r1r2 + r2r3 + r1r3 that is: current, voltage, resistance.

or voltage, resistance, and current.

What exactly is Ohm's law?

Understanding circuit diagrams is important to apply Ohm's law to solve problems. There are three ways to connect circuits: series, parallel, and mixed.

The hybrid circuit is more complex, but it is also composed of the simplest series and parallel connections. A single series (or parallel) as a unit. When analyzing the connection characteristics of the circuit, it is necessary to start with the most basic unit.

The characteristics of the three connected I, U, and R should be understood and remembered.

The i and u in the law correspond to r. r is the resistance (or total resistance) of a portion of the circuit. The resistance of a single appliance is its own resistance. The resistance of two appliances is calculated according to the way they are connected.

It is necessary to build confidence, perseverance in learning, and careful in analyzing circuits. Good luck with your studies!

Physics requires more questions and more familiarity with knowledge points. Every knowledge point must be understood thoroughly. Everything is the same. Good luck with your physics studies.

1. Ohm's law: The current in the conductor is directly proportional to the voltage at both ends of the conductor and inversely proportional to the resistance at both ends of the conductor. The formula is: i=u r, and the deformation formula is: u=ir, r=u i

2. Attention to the use of Ohm's law: the unit must be unified, the current is a, the voltage is v, and the resistance is used; It cannot be understood that the resistance is proportional to the voltage and inversely proportional to the current, because the resistance is not constant under normal circumstances.

3. The voltage of the electrical appliance when it is working normally is called the rated voltage; The current during normal operation is called the rated current; However, this standard is often not reached in life, so the voltage when the electrical appliance is actually working is called the actual voltage, and the current when it is actually working is called the actual current.

4. When there is a short circuit in the circuit (the power supply in the circuit is directly connected without passing through the electrical appliance), according to i=u r, it can be seen that because the resistance r is very small, the current will be very large, which will lead to fire.

5. Series and parallel connection of resistors:

Tandem: r=r1+r2+......rn (the total resistance of the series resistor is greater than the resistance of any one of the sub-resistors).

Parallel: 1 r=1 r1+1 r2+......1 rn (the total resistance of the parallel resistor is smaller than the resistance of any one of the sub-resistors).

n resistors with a resistance value r in series, then r total = nr; If n resistors with a resistance value of r are connected in parallel, then r total = r n exam book.