Magnetic Fields & Electromagnetism
According to the Biot-Savart Law, what happens to the magnetic field () if the current () in the wire increases?
The magnetic field () decreases.
The magnetic field () remains the same.
The magnetic field () increases.
The magnetic field () becomes zero.
A circular loop with a radius of 5 cm carries a current of 2 A. What is the magnitude of the magnetic field at the center of the loop?
Approximately 2.51 \times 10^{-5} T
Approximately 1.26 \times 10^{-5} T
Approximately 3.77 \times 10^{-5} T
Approximately 5.02 \times 10^{-5} T
A short wire segment of length 2 mm carries a current of 5 A. At a point 3 cm away, the magnetic field due to this segment is measured. If , what is the magnitude of the magnetic field ()?
Approximately 1.11 \times 10^{-10} T
Approximately 3.33 \times 10^{-11} T
Approximately 2.22 \times 10^{-11} T
Approximately 5.55 \times 10^{-11} T
A circular loop carries a current in a counter-clockwise direction. What is the direction of the magnetic field at the center of the loop?
Directed into the page.
Directed to the left.
Directed out of the page.
Directed to the right.
A wire carrying current is placed perpendicular to the page. At point P located to the right of the wire, the magnetic field is directed:
Toward the top of the page.
Toward the bottom of the page.
Toward the left of the page.
Toward the right of the page.
Under what condition is the force on a current-carrying wire in a magnetic field maximum?
When the wire is parallel to the magnetic field.
When the wire is at a 45-degree angle to the magnetic field.
When the wire is perpendicular to the magnetic field.
When there is no current in the wire.
A straight wire segment of length 0.2 m carries a current of 3 A in the positive y-direction. It is placed in a uniform magnetic field of 0.5 T pointing in the positive z-direction. What is the magnitude and direction of the force on the wire?
0.3 N in the positive x-direction
0.3 N in the negative x-direction
0.0 N
0.15 N in the positive x-direction

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Consider two current segments and each carrying current . They are positioned such that the magnetic field at point P due to is and due to is . If = (2,0,0) and = (0,3,0) , what is the net magnetic field at point P?
(2, 3, 0)
(2, 0, 0)
(0, 3, 0)
(2, 3, 0) T
Two concentric circular loops have radii and () and carry currents and respectively in the same direction. If the net magnetic field at the center is zero, what is the ratio of to ?
A straight wire carries a current in the upward direction. According to the right-hand rule, what is the direction of the magnetic field around the wire?
The magnetic field points radially inward towards the wire.
The magnetic field points radially outward away from the wire.
The magnetic field circles the wire in a clockwise direction.
The magnetic field circles the wire in a counter-clockwise direction.