Current Electricity Basics Quiz

Choose a study mode

Play Quiz

Study Flashcards

Spaced Repetition

Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following is a property of current electricity?

Its flow is independent of voltage
It cannot be used to power electronic devices
It is the flow of electric charge through a conductor (correct)
It only flows through insulators

What is the SI unit of electric current?

Ohm
Volt
Ampere (correct)
Watt

In which direction does conventional current flow?

From positive to negative (correct)
It can flow in both directions
It does not follow a specific direction
From negative to positive

What is the formula for calculating current density?

J = I/A Signup and view all the answers

How does an increase in cross-sectional area affect the current density?

An increase in cross-sectional area decreases the current density. Signup and view all the answers

Explain how current density is different from current?

Current density is the amount of current flowing through a unit area, while current is the flow of electric charge per unit time. Signup and view all the answers

What is the definition of current density?

The amount of charge per unit time that flows through a unit area of a chosen cross section. Signup and view all the answers

How is the current density vector defined?

As a vector whose magnitude is the electric current per cross-sectional area at a given point in space, with its direction being that of the motion of the positive charges at that point. Signup and view all the answers

What are the SI base units for measuring electric current density?

Amperes per square metre. Signup and view all the answers

How is the electric current density at a given point M calculated?

It is given by the limit of the electric current flowing through a small surface A centered at M and orthogonal to the motion of the charges at M. Signup and view all the answers

What is the relationship between charge density, velocity of charges, and electric current density?

The charge contained in the volume formed by the velocity and an infinitesimal surface will flow through that surface, and is given by the equation dq = ρ v dt dA. Signup and view all the answers