How do I calculate current?
Ohms Law and Power
- To find the Voltage, ( V ) [ V = I x R ] V (volts) = I (amps) x R (Ω)
- To find the Current, ( I ) [ I = V ÷ R ] I (amps) = V (volts) ÷ R (Ω)
- To find the Resistance, ( R ) [ R = V ÷ I ] R (Ω) = V (volts) ÷ I (amps)
- To find the Power (P) [ P = V x I ] P (watts) = V (volts) x I (amps)
When a 60 watt light bulb is connected to a 120 volt source the current in the light bulb is?
In fact, the 120-Watt bulb would have a current of 1 Amp and a resistance of 120 Ω; the 60-Watt bulb would have a current of 0.5 Amp and a resistance of 240 Ω.
What is the resistance of a 120 W incandescent lamp?
220 ohms
What is the current through the 2.0 Ω resistor?
Answer. Answer: The current through 2 ohm resistor is 2.1 A. Hence, the current through 2 ohm resistor is 2.1 A.
What is the potential difference across the 10?
Hence the potential difference at the 10 Ω resistor is 1.3 V.
How do you find the potential difference across a resistor?
The unit of potential difference generated between two points is called the Volt and is generally defined as being the potential difference dropped across a fixed resistance of one ohm with a current of one ampere flowing through it. In other words, 1 Volt equals 1 Ampere times 1 Ohm, or commonly V = I*R.
What is the potential difference across the 4 ohm resistor?
20 volts
What is the potential difference across A and B?
Thus the voltage across the resistance 4Ω is V=4Ω×1A=4V. Therefore the Potential difference across AB, i.e.,VA−VB is 10V. Hence,option (1) is the correct answer.
What is the formula of potential difference between two points?
The potential difference between two points ΔV is often called the voltage and is given by ΔV=VB−VA=ΔPEq Δ V = V B − V A = Δ PE q . The equation for the electric potential due to a point charge is V=kQr V = kQ r , where k is a constant equal to 9.0×109 N⋅m2/C2.
Why is voltage potential difference?
Voltage, also sometimes called potential difference or electromotive force (EMF), refers to the amount of potential energy the electrons have in an object or circuit. The more energy the electrons have, the stronger the voltage. The current means the rate of flow of electric charge.
Does higher voltage mean more electrons?
Voltage can no produce electrons so higher voltage can not increase the number of electrons. The potential difference only increases with the higher voltage.
What is potential difference in simple words?
Potential difference is the difference in the amount of energy that charge carriers have between two points in a circuit. **Measured in Volts: **Potential difference (p.d.) is measured in volts (V) and is also called voltage. We use a voltmeter to measure potential difference (or voltage).
Why is potential difference necessary for current?
Answer: Explanation: The potential difference applied to conductors to induce flow is the “pressure” that forces electrons to drift. Without it, there’s no cause for the electrons to drift in the same direction, so there will be no current. …
Why does current flow from positive to negative?
The direction of an electric current is by convention the direction in which a positive charge would move. Thus, the current in the external circuit is directed away from the positive terminal and toward the negative terminal of the battery. Electrons would actually move through the wires in the opposite direction.
Why battery has positive and negative?
The cathode and anode (the positive and negative sides at either end of a traditional battery) are hooked up to an electrical circuit. The chemical reactions in the battery causes a build up of electrons at the anode. Electrons repel each other and try to go to a place with fewer electrons.
Why does current flow from high potential to low potential?
Answer Expert Verified So electrons drift in the opposite direction from – to + terminal. move from a higher energy point to a lower energy point, current flows from a higher energy point or higher potential (+terminal) to a lower energy point or potential (- terminal).
Which type of circuit has only one way for electricity to flow?
Series Configuration Circuit
Does voltage flow from negative to positive?
Electrical engineers say that, in an electrical circuit, electricity flows one direction: out of the positive terminal of a battery and back into the negative terminal. Electronic technicians say that electricity flows the other direction: out of the negative terminal of a battery and back into the positive terminal.
What is negative and positive in electricity?
There are two types of electric charge: positive and negative (commonly carried by protons and electrons respectively). Like charges repel each other and unlike charges attract each other. In ordinary matter, negative charge is carried by electrons, and positive charge is carried by the protons in the nuclei of atoms.
What is the voltage coming into my house?
240 volts
Does power increase with resistance?
1. Why do incandescent lightbulbs grow dim late in their lives, particularly just before their filaments break? The power dissipated in a resistor is given by P = V2/R which means power decreases if resistance increases. Yet this power is also given by P = I2R, which means power increases if resistance increases.
What happens to voltage if resistance increases?
Ohm’s law states that the electrical current (I) flowing in an circuit is proportional to the voltage (V) and inversely proportional to the resistance (R). Similarly, increasing the resistance of the circuit will lower the current flow if the voltage is not changed.
What happens to the current as the resistance decreases?
Answer: The current increases as the resistance decreases and the current decreases as the resistance increases.
Does current affect resistance?
An electric current flows when electrons move through a conductor, such as a metal wire. This makes it more difficult for the current to flow, and causes resistance. The resistance of a long wire is greater than the resistance of a short wire because electrons collide with more ions as they pass through.
What does specific resistance depend on?
Specific resistance or resistivity depends upon the temperature of the conductor and the nature of the material the conductor is made up of.
What is difference between resistance and specific resistance?
The resistance between two ends of a wire is the ratio of the potential difference of the two points to the current flowing through the conductor. Resistivity or specific resistance of a material is defined as the resistance of unit length and unit cross-section of that material.
What is the specific resistance of a wire?
The specific resistance or resistivity of a wire is the property of the material of it. It does not depend on mass, length or cross-section of wire.
What is the formula of specific resistance?
Specific Resistance (”ρ”) is a property of any conductive material, a figure used to determine the end-to-end resistance of a conductor given length and area in this formula: R = ρl/A. Specific resistance for materials are given in units of Ω-cmil/ft or Ω-meters (metric).
What is specific resistance and write its unit?
The SI unit of resistivity is Ohm (Ω . m) whereas the unit of resistance is Ohm. 3. What is the Specific Resistance Value of Copper Conductor?…The Specific Resistance of Various Materials.
| Conductors |
| Material |
Resistivity in Ohm meter unit |
| Diamond |
1012 |
| Air |
109 – 1015 |
What is Ohm’s law define specific resistance?
I=VR I = V R . This relationship is also called Ohm’s law. Ohm’s law in this form really defines resistance for certain materials. Ohmic materials have a resistance R that is independent of voltage V and current I. An object that has simple resistance is called a resistor, even if its resistance is small.
Is V IR Ohm’s law?
Ohm’s Law is V = IR, where V = voltage, I = current, and R = resistance. Ohm’s Law allows you to determine characteristics of a circuit, such as how much current is flowing through it, if you know the voltage of the battery in the circuit and how much resistance is in the circuit.
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