Magnetic Field Questions and Answers

A 5.00-m straight conductor carries[a current of 15.0 A through a uniform magnetic field. The magnitudeof the force on the conductor is 0.67 N. The angle between the current and the magnetic field is 50.0°. What is the magnitude of the magnetic field? [A=5]

4. The magnetic field inside a solenoid resembles that of a: electric generator a bar magnet electric motor a u-shaped magnet

7. A current-carrying wire carries a current of 1.84 A. How far away from the wire is point P if the magnetic field at that location is 6.88 x 10-6 T? 0.535 A 0.0535 A 0.0747 A O 0.747 A

9. Which of the following electromagnet will have the strongest force? A battery with 15 loops of wire around the nail. A battery with 3 loops of wire around the nail. A battery with no loops of wire around the nail. A battery with 10 loops of wire around the nail. MALIL

1. Which of the following are true? Select all that apply. When more wraps are added to a secondary coil in a transformer the voltage decreases. When more wraps are added to a primary coil in a transformer the voltage decreases. When more wraps are added to a primary coil in a transformer the voltage increases. When more wraps are added to a secondary coil in a transformer the voltage increases.

2. An electron moving straight down (into the page) at å speed of 2.75 x 107 m/s experiences a force of 6.07 x 10-12 N directly east. What direction is the magnetic field pointing? west out of the page north south

6. A current-carrying wire placed in a magnetic field will be deflected by a force that is proportional to: (check all that apply) the type of wire moving in the magnetic field the length of wire in the magnetic field the strength of the magnetic field the current flowing through the wire

6. When was the first compass used for navigation in Europe? the 1900's the 1500's the 1100's the 1800's

2. What are the advantages of an electromagnet over a regular magnet? Select all that apply. You can cut it in half and have two magnets. You can increase the strength of the magnet. You can switch the location of the poles. You can turn the magnet off and on.

3. Which of the following is true about an electromagnet? Select all that apply. Increasing the current flowing through the wire makes a strong magnet. Decreasing the number of coils around the core makes a strong magnet. Decreasing the current flowing through the wire makes a stronger magnet. Adding more coils around the core makes a stronger magnet.

8. The strength of the magnetic field around a current-carrying wire is directly proportional to: the square of the distance from the wire the square of the current through the wire the current through the wire the distance from the wire

10. (a) Calculate the speed of a proton with mass 1.67 10-27 kg, travelling a circular path through a radius of 8.0 cm, in a plane perpendicular to a 4.2-T magnetic field. [T/I=3] (b) What potential difference would be required to accelerate the proton from rest in a vacuum to this speed? [T/I=3]

Question 7 A circular loop of diameter 10 cm, carrying a current of 0.20 A, is placed inside a magnetic field B = 0.30 Tk. The normal to the loop is parallel to a unit vector " = -0.60 i - 0.80 i. Calculate the magnitude of the torque on the loop due to the magnetic field. 4.7 x 10-4 N . m 2.8 x 10-4 N•m 1.2 × 10-4 N.m 1.2 x 0.60 × 10-4 N•m 1 pts zero

You make a circular wire loop that can expand and contract (radius isn't held constant) as well as spin. When it carries current in a magnetic field, which of the following is possible? the loop can spin the loop can shrink all of these the loop can expand

In the Arctic, a 20 A current flows in a 20 km length of wire from North to South within the Earth's vertically downward magnetic field, B, of 3 x 10^-5 Tesla. Compute the magnitude of the magnetic force acting on the wire. Sketch and show the direction of the force on the wire.

You're measuring a magnetic field B in a lab. In order to do so, you measure its components (in units of tesla) to be Bx = 1 tesla, By = -3 tesla, B₂ = 5 tesla. • What's the magnitude of this magnetic field? •How would you draw an illustration of this magnetic field? OR what makes it difficult to draw an illustration of this magnetic field?

A frog can be levitated in magnetic field produced by a current in a vertical solenoid placed below the frog. This is possible because the body of the frog behaves as A Paramagnetic B Diamagnetic C Ferromagnetic D Anti-ferromagnetic

An ice skater is moving across the skating rink and speeding up. Which one of the following statements is true of the ice skater? Its kinetic energy is increasing and its potential energy is decreasing. Its kinetic energy is increasing and its potential energy is constant. Both its kinetic energy and its potential energy are constant. Its kinetic energy is constant and its potential energy is increasing. Its kinetic energy is decreasing and its potential energy is increasing.

If the loops each have a radius of 3.0 cm and they each carry a current of 2.1 A, determine the magnitude of the net magnetic field at the common center. (b) The direction of a vector in three dimensions is often given by the angle it makes with the positive x, y, and z-axes. What is the angle between the net magnetic field at the center and the positive x-axis? What is the angle between the net magnetic field at the center and the positive y-axis? What is the angle between the net magnetic field at the center and the positive z-axis?

At a particular instant a proton is at the origin, moving with velocity < 5 x 104, -3 x 104, -7 x 104 m/s. At this instant: (a) What is the electric field at location <3 x 10-3, 2 x 10-3, 4 x 10-3> m, due to the proton? (b) What is the magnetic field at the same location due to the proton?

A square loop of each side as 'a' and a circular loop with the diameter of length 'a' lie in the xy-plane, where there is a uniform magnetic field B pointing at an angle with the positive z-direction. Each loop carries the same current, in the same sense (clockwise or counterclockwise). Which magnetic torque is larger? By what ratio? (Take the torque T for square, Te for the circle) TS is greater than Te where Ts/ Tc = 8/1. T, is greater than Te where Ts/ Tc 2/3m. T, is greater than T where T₁/T4/T. T is greater than 7, where Tc/ T₂ = 4/H.

The figure below shows the schematic for a mass spectrometer which consists of a velocity selector and a deflection chamber. The magnitude of the magnetic field in both the velocity selector and the deflection chamber is 0.0810 T, and the electric field between the plates of the velocity selector is 5100 V/m. If a singly charged ion with a mass of 5.02 x 10-27 kg travels through the velocity selector and into the deflection chamber, determine the radius of its trajectory in the deflection chamber.

Which of the following actions will help limit the access to your network? Turn off the wireless connection when it is not in use Enable the network to look for active devices Disable firewall guards

Which of the following happens when individuals respond cognitively to conflict? 1.Their heartbeat becomes rapid and perspiration increases. 2.They begin to have mental conversations about the situation. 3.They experience body tension, tunnel vision, and nausea. 4.They experience shallow or increased breathing.

Which statement(s) is/are true about elastic collisions? Select all that apply. 1.total kinetic energy of the system is conserved 2.center of mass can accelerate 3.momentum of the center of mass is conserved 4.There is no net external force acting on the system. 5.individual kinetic energies of colliding objects are conserved 5.total momentum of the system is conserved 6.individual momenta of colliding objects are conserved

A segment of a wire which carries a current does not experience a magnetic field. How is the wire possibly oriented for this to be true? A. The wire's current is perpendicular to the magnetic field. B. The magnetic field cycles around the wire. C. The wire's current is in the same direction as the magnetic field. D. The wire's current is in the opposite direction as the magnetic field.

A power line lies along the east-west direction and carries a current of 10 A. The force acting on a 1m segment due to Earth's magnetic field of 10-5 Tis 10-5 N 10-4 N 10-3 N 10-² N

A vibrating object makes 35.2 complete back and forth vibrations in 21.9 seconds with a velocity of 31.1 m/s. Find the wavelength of the wave. Your answer needs three digits (nonzeros).

e = 1.6.1019 Coulomb, k = 9.1019 (S.I). Ho-4 r. 107 (S.I.). 25 points each soeu. QUESTIONS 1. A rectangular loop carrying current I is placed between the poles of a magnet, parallel to the magnetic field, as shown in Figure 1. The width of the rectangle is d and its length is L. a. Calculate the theoretical expression of the torque acting on the circuit. b. Calculate Torque if d=0.40 m, L=0.60 m, B= 4 milliTesla and 1=2 amps?

A coil of insulated wire is wound many times around an iron bar. The wire is connected to a battery and a contact switch. The contact switch is alternately flipped closed and left closed, so the wire carries a current through it, and then flipped open and left open, so that the current stops. Describe what magnetic fields are created, if those magnetic fields in turn induce an emf, and whether the induced emf is in the direction of the original current or opposite to it. Justify your answer using Lenz's law and the conditions which can cause a magnetic field to induce an emf. You may draw a diagram if it helps you to visualize the apparatus.

If you were to cut a small permanent bar magnet in half, A. one piece would be a magnetic north pole and the other piece would be a south pole. B. neither piece would be magnetic. C. each piece would in itself be a smaller bar magnet with both north and south poles. D. None of these statements is true.

Forces between two objects which are inversely proportional to the square of the distance between the objects include which of the following? Select two answers: a. Gravitational force between two celestial bodies b. Electrostatic force between two electrons c. Nuclear force between two neutrons d. Magnetic force between two magnets

Two long parallel wires separated by 7.5 cm each carry 3.3 A in opposite directions. Find the magnitude of the magnetic field midv between the two wires. A. 3.0x10-4 T B. 3.5x10-5 T C. 1.8x10-3 T D. 5.2x10-4T

A small electric car overcomes a 250-N friction force when traveling 35 km/h. The electric motor is powered by ten 12-V batteries connected in series and is coupled directly to the wheels whose diameters are 58 cm. The 290 armature coils are rectangular, 12 cm by 15 cm, and rotate in a 0.65-T magnetic field. a. How much current does the motor draw to produce the required torque? b. What is the back emf? c. How much power is dissipated in the coils? d. What percent of the input power is used to drive the car?

A very long straight current carrying wire produces a magnetic field of 20 mT at a distance d from the wire. To measure a field of 5 mT due to this wire, you would have to go to a distance from the wire of A. 4 d B. 2 d C. 8 d D. 16 d

The maximum magnitude of the magnetic torque exerted on a flat current-carrying loop of wire by a uniform magnetic field depends on the exact shape of the loop is independent of the area of the loop is independent of the magnetic moment is when the plane of the loop is parallel to the magnetic field is when the plane of the loop is perpendicular to the magnetic field

From the textbook reading, find the equation that can be used to predict the strength of the magnetic field around a long, straight, current-carrying wire. Write down that equation and describe what each of the symbols mean in words.

You try to live strictly by the moral rules contained in your religion's moral code. The two most important rules are "Be merciful" (don't give people what they deserve) and "Be just" (give people exactly what they deserve). Now suppose a man is arrested for stealing food from your house, and the police leave it up to you whether he should be prosecuted for his crime or set free. Should you be merciful and set him free, or be just and make sure he is appropriately punished? How do you resolve this conflict of rules? Can your moral code resolve it? To what moral principles or theories do you appeal?

Electrons with kinetic energy K are injected into the space between two parallel conducting plates a distance d apart, connected to a battery of emf E. A magnetic field is applied to cause the electrons to travel in straight lines. c) Evaluate B if d = 5.0 mm, ε = 48 V, K = 71 eV.

Q3) Each phase of a balanced three-phase -connected load consists of a 200 mH inductor in series with the 200 resistance. Assume zero-line resistance and a phase voltage of 200 V at = 400 rad/s. Find (a) the phase current; (b) the line current; (c) the total power absorbed by the load.

A magnetic field of a magnet is best described as: a) the strength of a magnet b) The area around a magnet where its influence can be detected. c) an atom that is negatively charged d) a metal that can be magnetized by induction e) the poles of a magnet

[6 pts] After placing the CRT into the center of the solenoid, you start increasing the current steadily until you find the value of current needed to calculate the charge-to-mass ratio of the electron. How can you tell that the value shown on the power supply is the right one to use? (What will the "signal" look like on the CRT screen?)

A long, horizontal wire is carrying a current I. A particle of mass m and charge q is fired horizontally at a speed vo. The initial velocity of the particle is parallel to the wire, and its initial position is a distance r directly below the wire, as shown in (Figure 1). What initial speed must the particle have for it to travel in a straight line? Do not ignore gravity. Express your answer in terms of I, m, q, T, μo, and the acceleration of gravity g. Determine at what initial speed Vo the particle will travel in a straight horizontal line. Review I Constants

Q11. The electric field of a plane electromagnetic wave in vacuum is represented by, Ex= 0, Ey= 0.5 cos[2T X 108(t-1)] and E₂= 0 (i) What is the direction of propagation of electromagnetic wave? (ii)Determine the wavelength of the wave. (iii) Compute the component of associated magnetic field.

A particle having mass m and charge +q is released from rest in uniform electric and magnetic field perpendicular to each other then maximum speed of particle (m/s) during motion will be : (E = 232 N/c, B = 5T, q = 2mc, m = 1gm)

A duck flying due east passes over Atlanta, where the magnetic field of the Earth is 5.6 × 10-5 T directed north. The duck has a positive charge of 4.0 × 10-8 C. If the magnetic force acting on the duck is 3.60 x 10 N upward, what is the magnitude of the duck's velocity? 1. 21.8182 2. 8.63636 3. 16.0714 4. 4.16667 5. 19.9153 6. 19.3966 7. 28.9216 8. 4.82456 9. 13.4615 10. 16.3636 Answer in units of m/s.

A 0.230 m radius, 485 turn coil is rotated one-fourth of a revolution in 4.17 ms, originally having its plane perpendicular to a uniform magnetic field. (This is 60 rev/s.) Find the magnetic field strength needed to induce an average emf of 10,000 V.

A 0.2 baseball if pitched with a velocity of 40 m/s and is then batted to the pitcher with a velocity of 60 m/s. What is the magnitude of change in the ball's momentum? A. 2 kg-m/s B. 8 kg-m/s C. 20 kg-m/s D. 4 kg-m/s

14. Math Connection The magnetic field around a current-carrying wire at a distance of 1 cm is twice as strong as at 2 cm. How does the field strength at 0.5 cm compare to the field strength at 1 cm?

How far from the starter cable of a car, carrying 170 A, must you be to experience a field less than the Earth's (4.85 x 10-5 T)? Assume a long, straight wire carries the current. (In practice, the body of your car shields the dashboard compass.)