Content Curator
Potential difference is the difference in electric potential between the two points and is defined as work done in moving a unit positive test charge from one point to another point in an electric field.
- It is also known as voltage, electric pressure, and electric tension.
- The SI unit of potential difference is volt (V).
- The electric potential produced within an electrochemical cell or by changing the magnetic field is referred to as electromotive force (EMF).
- A resistor is a two-terminal passive electrical component that makes use of electrical resistance as a circuit element. Resistors are used in electronic circuits to limit current flow.
- The electrical resistance of an object is a measure of its opposition to the flow of electric current.
- The SI unit of electrical resistance is ohm (Ω).
Ohm's law states that if all physical conditions and temperatures are constant, the potential difference across a conductor is directly proportional to the current flowing through it. According to Ohm’s law
V = IR
Where
- V is the potential difference across the conductor.
- R is the resistance of the conductor
- I is the current flowing through the conductor
Ques. Define electromotive force.
Ans. Electromotive force (emf) is defined as the transmission of energy to an electric circuit per unit of electric charge, expressed in volts. Electrical transducers produce an EMF by converting various types of energy into electrical energy.
Ques. Define terminal voltage.
Ans. Terminal voltage is defined as the potential difference between the two terminals when the circuit is closed.
Ques. Define electrical resistivity.
Ans. Electrical resistivity, also known as the specific resistance of a material is equal to the resistance of the object of 1 m length and 1 m2 area of cross section.
It is a fundamental material characteristic that determines electrical resistance, or how strongly a substance resists electric current.
Ques. Which instrument is used to measure the terminal voltage?
Ans. A voltmeter is used to measure the terminal voltage across an element of the circuit.
Ques. What is Ohm’s law?
Ans. According to Ohm’s law, the current flowing through a conductor is directly proportional to the potential difference across the ends of the conductor provided that physical conditions like temperature, strain, pressure, etc. of the conductor remain unchanged.
Ques. Define electric current.
Ans. The flow of charged particles, such as electrons or ions, traveling through an electrical conductor or space is referred to as an electric current. It is defined as the net rate of charge flow through a surface.
Ques. What is the magnitude of charge in an electron?
Ans. An electron is a negatively charged particle revolving around the nucleus of an atom. The magnitude of charge an electron has is 1.6 x 10-19 C.
Ques. Define 1 ohm.
Ans. One ohm is defined as an object's resistance when a current of one ampere travels through an object having a potential difference of one volt.
Ques. Define the potential difference.
Ans. The amount of work done in transferring a unit positive charge without acceleration from one location to another along any path between the two points in the electric field is defined as the potential difference between the two points.
Ques. What is the SI unit of potential difference?
Ans. The SI unit of potential difference is volt.
Ques. What is the formula of Ohm’s law?
Ans. Ohm’s law can be represented by the formula
V = IR
Where
- V is the potential difference across the terminals of the circuit
- I is the current flowing through the circuit
- R is the resistance of the circuit
Ques. What is coulomb?
Ans. Coulomb is a SI unit of electric charge defined as the amount of charge in 6.25 x 1018 electrons.
Ques. What are the factors that affect the resistivity of a conductor?
Ans. The following factors affect the electrical resistivity of a conductor
- Temperature
- Alloying
- Mechanical stressing
- Age Hardening
- Cold Working
Ques. Can EMF be negative?
Ans. Yes, the EMF can be negative. A negative sign in EMF indicates that the generated EMF is directed in the opposite direction as the original.
Ques. What is the relationship between terminal potential difference and EMF?
Ans. The relationship between the terminal potential and EMF is given by the relation
V = E – Ir
Where
- V is the terminal potential difference
- E is the EMF of a cell
- I is the current flowing through the circuit
- r is the internal resistance of the cell
Ques. What is the SI unit of electric charge?
Ans. The SI unit of electric current is Coulomb (C).
Ques. How is resistance proportional to length?
Ans. The resistance of a material is directly proportional to its length. The value of resistance increases as the length of the material increases. When the length of a material decreases, its resistance value also decreases.
Ques. Why is area inversely proportional to resistance?
Ans. The area of the cross-section is inversely proportional to resistance. The resistance inside a conductor is caused by the collision of charged particles or electrons with each other. As the area of the conductor's cross-section increases, the space between charged particles will also be increased. Hence the probability of electron collisions will decrease, which decreases the resistance of the conductor.
Ques. What is an ammeter?
Ans. An ammeter is a device that measures the current in a circuit. The term comes from the fact that electric currents are measured in amperes. The ammeter is connected in series with the circuit in which the current is to be measured for direct measurement.
Ques. What is a voltmeter?
Ans. A voltmeter is a device that measures the difference in electric potential between two points in an electric circuit. It is connected in parallel. It generally has a high resistance and draws very little current from the circuit.
For Latest Updates on Upcoming Board Exams, Click Here: https://t.me/class_10_12_board_updates
Also Check:
Comments