The dipole magnetic moment ( μ) is directly proportional to nuclear spin ( I), connected by a constant called the.The energy is at its maximum (not a minimum), when the dipole points opposite the field ( θ = 180°), so answer a) is false. The energy ( E) is defined by the dot product, E = − μ In terms of scalar magnitudes: || τ|| = || μ|| || B 0|| sin θ, where θ is the angle between them. The dipole ( μ) experiences a torque ( τ) given by the vector cross-product τ = μ x B 0. The energy of the dipole-external field system depends on the angle between the dipole and the external field.The torque (twisting force) experienced by the dipole depends on the angle between the dipole and the external field.The torque (twisting force) experienced by the dipole is directly proportional to the strength of the external field.The dipole is at its lowest energy state when pointing in a direction opposite the field.Which of the following statements about a magnetic dipole placed in an external magnetic field is false?.The magnetic dipole moment ( μ) will experience a torque causing it to align with an externally applied magnetic field, but will not precess around the field. The dipole moment will precess when placed in an external magnetic field.Like a compass needle, a dipole moment will tend to align with an externally applied magnetic field to assume its lowest energy state.An alternative representation is a vector ( μ) arising from a small current loop.It is a representation of the nucleus modeled as a tiny bar magnet with north and south poles.Which of the following statements concerning the magnetic dipole moment is false?.Only nuclei with non-zero spins can undergo NMR, so d) is false. Across the periodic table nuclear spins ( I) with values ranging from 0 to 8 can be found.Every element in the periodic table has at least one isotope that can undergo NMR.All nuclei can undergo NMR except those containing even numbers of both protons and neutrons.Concerning nuclear spin ( I) and NMR, which of the following statements is false?.The other statements - a), c) and d) - are all true. Net nuclear spin ( I) does depend on the total number of protons and neutrons, but no simple formula for I exists as interactions between more elementary components (quarks and gluons) must be considered. Every element has at least one isotope with non-zero spin.Different isotopes of the same element commonly have different nuclear spins.To determine net nuclear spin ( I), you simply add up the number of protons and neutrons and divide by 2.Protons and neutrons each have spin = ½.The hydrogen (¹H) nucleus contains only a single proton surrounded by an electron cloud, so d) is false. The hydrogen (¹H) nucleus contains one proton and one electron.Routine clinical MRI measures signal from hydrogen (¹H) nuclei only.For hydrogen (¹H) MRI it is common and acceptable to use the terms "nucleus", "spin", and "proton" interchangeably.A longer but equivalent name for "spin" is "spin angular momentum".Concerning nuclear spin ( I), which of the following statements is false?.Quantum mechanics restricts nuclear spin to only integer or half-integer (1/2, 3/2, 5/2, etc) values, so I = 3/4 is not permitted. Which of the following spins ( I) could a nucleus not possess?.When placed in an external magnetic field, nuclear spin results in precession, but spin and precession are not the same. Spin is quantized and can take on a limited number of discrete values, so c) is true. Many subatomic particles besides the proton have spin, including the neutrons and electrons. Spin is a fundamental quantum property of subatomic particles and does not result from their physical rotation. Spin can only have integer or half-integer values.Protons have spin, but neutrons do not.Spin is due to rotation of the nucleus about its axis.Concerning nuclear spin ( I), which of the following is true?.
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