Exam 27: Magnetic Interactions

As shown in the figure,a small particle of charge q = -7.0 × 10^-6 C and mass m = 3.1 × 10^-12 kg has velocity v₀ = 9.4 × 10³ m/s as it enters a region of uniform magnetic field.The particle is observed to travel in the semicircular path shown,with radius R = 5.0 cm.Calculate the magnitude and direction of the magnetic field in the region.

A wire along the z-axis carries a current of 6.8 A in the +z direction.Find the magnitude and direction of the force exerted on a 6.1-cm long length of the wire by a uniform magnetic field with magnitude 0.36 T in the -x direction.

A horizontal wire carries a current straight toward you.From your point of view,the magnetic field at a point directly below the wire points

A wire carries a 4.0-A current along the +x-axis through a magnetic field = (5.0 + 7)0 )T) If the wire experiences a force of 30 N As a result,how long is the wire?

A thin copper rod that is 1.0 m long and has a mass of 0.050 kg is in a magnetic field of 0.10 T. What minimum current in the rod is needed in order for the magnetic force to cancel the weight of the rod?

An electron traveling toward the north with speed 4.0 × 10⁵ m/s enters a region where the Earth's magnetic field has the magnitude 5.0 × 10^-5 T and is directed downward at 45° below horizontal. What is the magnitude of the force that the Earth's magnetic field exerts on the electron? (e = 1.60 × 10^-19C)

Alpha particles (charge = +2e,mass = 6.68 × 10^-27 kg,e = 1.60 × 10^-19C)0.87 μs.

A uniform magnetic field of magnitude 0.80 T in the negative z-direction is present in a region of space,as shown in the figure.A uniform electric field is also present.An electron that is projected with an initial velocity v₀ = 9.1 × 10⁴ m/s in the positive x-direction passes through the region without deflection.What is the electric field vector in the region?

A vertical wire carries a current vertically upward in a region where the magnetic field vector points toward the north.What is the direction of the magnetic force on this current due to the field?

An electron,moving toward the west,enters a uniform magnetic field.Because of this field the electron curves upward.The direction of the magnetic field is

An L-shaped metal machine part is made of two equal-length segments that are perpendicular to each other and carry a 4.50-A current as shown in the figure.This part has a total mass of 3.80 kg and a total length of 3.00 m,and it is in an external 1.20-T magnetic field that is oriented perpendicular to the plane of the part,as shown.What is the magnitude of the NET magnetic force that the field exerts on the part?

A rigid rectangular loop,which measures 0.30 m by 0.40 m,carries a current of 5.5 A,as shown in the figure.A uniform external magnetic field of magnitude 2.9 T in the negative x direction is present.Segment CD is in the xz-plane and forms a 35° angle with the z-axis,as shown.Find the magnitude of the external torque needed to keep the loop in static equilibrium.

A charge is accelerated from rest through a potential difference V and then enters a uniform magnetic field oriented perpendicular to its path.The field deflects the particle into a circular arc of radius R.If the accelerating potential is tripled to 3V,what will be the radius of the circular arc?

A charged particle of mass 0.0020 kg is subjected to a 6.0 T magnetic field which acts at a right angle to its motion.If the particle moves in a circle of radius 0.20 m at a speed of 5.0 m/s,what is the magnitude of the charge on the particle?

A wire segment 1.2 m long carries a current I = 3.5 A,and is oriented as shown in the figure.The +x-axis points directly into the page.A uniform magnetic field of magnitude 0.50 T pointing toward the -x direction is present as shown.What is the magnetic force vector on the wire segment?

An electron moving in the direction of the +x-axis enters a magnetic field.If the electron experiences a magnetic deflection in the -y direction,the direction of the magnetic field in this region points in the direction of the

A wire segment 1.2 m long carries a current I = 3.5 A and is oriented as shown in the figure.A uniform magnetic field of magnitude 0.50 T pointing toward the -x direction is present as shown.The +z-axis points directly into the page.What is the magnetic force vector on the wire segment?

A uniform magnetic field of magnitude 0.80 T in the negative z direction is present in a region of space,as shown in the figure.A uniform electric field is also present and is set at 76,000 V/m in the +y direction.An electron is projected with an initial velocity v₀ = 9.5 × 10⁴ m/s in the +x direction.The y component of the initial force on the electron is closest to which of the following quantities? (e = 1.60 × 10^-19C)

A proton is first accelerated from rest through a potential difference V and then enters a uniform 0.750-T magnetic field oriented perpendicular to its path.In this field,the proton follows a circular arc having a radius of curvature of 1.84 cm.What was the potential difference V? (m_proton = 1.67 × 10^-27 kg, e = 1.60 × 10^-19 C)

An electron moves with a speed of 8.0 × 10⁶ m/s along the +x-axis. It enters a region where there is a magnetic field of 2.5 T,directed at an angle of 60° to the +x-axis and lying in the xy-plane. (1 eV = 1.60 × 10^-19 C,m_el = 9.11 × 10^-31 kg)Calculate the magnitude of (a)the magnetic force on the electron. (b)the acceleration of the electron.