Concept explainers
Explain the difference between current and current density.
The difference between current and current density.
Answer to Problem 1FTD
Electric current is a scalar quantity and current density is a vector quantity. That is electric current has magnitude only but electric current density has both direction and magnitude and also electric current is the flow of charges but current density is the amount of current passing per unit area.
Explanation of Solution
Electric current is the time rate of flow of charges or ions. It is measured using the apparatus called ammeter and the unit of current is ampere. The magnitude of current depends on the potential difference and the resistance.
Write the equation to find the electric current.
Here,
The magnitude of current increases as the number of charges increases.
Write the equation to find the current density.
Here,
The current density can be explained as the amount of current passing through unit area. Current densities are denoted by the symbol
Conclusion:
Electric current is a scalar quantity and current density is a vector quantity. That is electric current has magnitude only but electric current density has both direction and magnitude and also electric current is the flow of charges but current density is the amount of current passing per unit area.
Want to see more full solutions like this?
Chapter 24 Solutions
Essential University Physics (3rd Edition)
Additional Science Textbook Solutions
Physics for Scientists and Engineers with Modern Physics
University Physics with Modern Physics (14th Edition)
Lecture- Tutorials for Introductory Astronomy
Tutorials in Introductory Physics
Physics: Principles with Applications
University Physics (14th Edition)
- A 14-gauge copper wire has a diameter of 1.628 mm. What magnitude current flows when the drift velocity is 1.00 mm/s? (See above example on Example 20.3 for useful information.)arrow_forwardWhen 100.0 V is applied across a 5-gauge (diameter 4.621 mm) wire that is 10 m long, the magnitude of the current density is 2.0X108A/m2 . What is die resistivity of the wire?arrow_forwardConsider a square rod of material with sides of length L = 3.00 cm with a current density of J=J0eaxk=(0.35Am2)e(2.1103m1)xk as shown below. Find the current that passes through the face of the rod.arrow_forward
- A total of 600 C of charge passes through a flashlight in 0.500 h. What is the average current?arrow_forwardThe current supplied by a battery in a portable device is typically 0.15 A. Find the number of electrons passing through the device in one hour.arrow_forwardThe current of an electron beam has a measured current of I=50.00A with a radius of 1,00 mm2. What is the magnitude of the current density of the beam?arrow_forward
- The current supplied by a battery in a portable device is typically 0.15 A. Find the number of electrons passing through the device in one hour.arrow_forwardA current-carrying copper wire with cross-section =2mm2 has a drift velocity of 0.02cm/s. Find the total current running through the wire.arrow_forwardCan a wire cany a current and still be neutral—that is, have a total charge of zero? Explain.arrow_forward
- Check Your Understanding The current density is proportional to the current and inversely proportional to the area. If the current density in a conducting wire increases, what would happen to the drift velocity of the charges in the wire?arrow_forwardThe current supplied to an ail conditioner unit is 4.00 amps. The air conditioner is wired using a 10-gauge (diameter 2.588 mm) wire. The charge density is n=8.481028electronsm3 Find magnitude of (a) current density and (b) the drift velocity.arrow_forwardDiscuss how the Hall effect could be used to obtain information on free charge density in a conductor. (Hint: Consider how drift velocity and current are related.)arrow_forward
- University Physics Volume 3PhysicsISBN:9781938168185Author:William Moebs, Jeff SannyPublisher:OpenStaxPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax CollegePrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning