CURRENT ELECTRICITY Flashcards
What is the SI unit of electric current?
The SI unit of electric current is the Ampere (A).
True or False: Current is defined as the flow of electric charge.
True
Fill in the blank: The relationship between voltage (V), current (I), and resistance (R) is given by __________.
Ohm’s Law
What does Ohm’s Law state?
Ohm’s Law states that the current through a conductor between two points is directly proportional to the voltage across the two points.
What is the formula for calculating resistance?
Resistance (R) is calculated using the formula R = V/I, where V is voltage and I is current.
What is the unit of resistance?
The unit of resistance is the Ohm (Ω).
In a series circuit, how is the total resistance calculated?
In a series circuit, the total resistance is the sum of all individual resistances: R_total = R1 + R2 + R3 + …
In a parallel circuit, how is the total resistance calculated?
In a parallel circuit, the total resistance is given by the formula 1/R_total = 1/R1 + 1/R2 + 1/R3 + …
What is the effect of increasing resistance on current in a circuit with constant voltage?
Increasing resistance decreases the current in a circuit with constant voltage.
What does a voltmeter measure?
A voltmeter measures the electric potential difference (voltage) between two points in a circuit.
What does an ammeter measure?
An ammeter measures the electric current flowing through a circuit.
True or False: In series circuits, the current is the same through all components.
True
What happens to voltage across each component in a series circuit?
The total voltage is divided among the components in a series circuit.
What is Kirchhoff’s First Law?
Kirchhoff’s First Law states that the total current entering a junction equals the total current leaving the junction.
What is Kirchhoff’s Second Law?
Kirchhoff’s Second Law states that the sum of the electromotive forces (emf) in any closed loop is equal to the sum of the potential drops in that loop.
What is the significance of resistivity?
Resistivity is a material property that quantifies how strongly a given material opposes the flow of electric current.
What is the formula for resistivity?
Resistivity (ρ) is calculated using the formula ρ = R(A/L), where R is resistance, A is cross-sectional area, and L is length.
What is the relationship between temperature and resistance in conductors?
In conductors, resistance typically increases with an increase in temperature.
What is the formula for electric power in a circuit?
Electric power (P) is calculated using the formula P = VI, where V is voltage and I is current.
Fill in the blank: The total power consumed in a series circuit is __________ the sum of the powers consumed by each component.
equal to
What is the equivalent resistance of two resistors, R1 and R2, in series?
R_eq = R1 + R2
What is the equivalent resistance of two resistors, R1 and R2, in parallel?
1/R_eq = 1/R1 + 1/R2
True or False: The total current in a parallel circuit is the sum of the currents through each branch.
True
What is the purpose of a fuse in an electrical circuit?
A fuse is used to protect an electrical circuit by breaking the circuit if the current exceeds a certain level.
