DON.E CONSULT TWO WEEKS TUTORIAL 20 QUESTIONS ON MAGNETISM 1)At any point the magnetic field lines are in the direction of: A. the magnetic force on a moving positive charge B. the magnetic force on a moving negative charge C. the velocity of a moving positive charge D. none of the above 2) The units of magnetic dipole moments are: A. ampere B. ampere meter C. ampere (meter)² D. ampere/meter 3)The current flowing through a long straight wire is 160 A. Determine the magnetic field due to a current at a distance of 4mm from the wire. A. 0.008 T B. 0.003 T C. 0.002 T D. 0.004 T 4) At any point the magnetic field lines are in the direction of: A. the magnetic force on a moving positive charge B. the magnetic force on a moving negative charge C. the velocity of a moving positive charge D. none of the above 5) The units of magnetic dipole moments are: A. ampere B. ampere meter C. ampere (meter)² D. ampere/meter 6)The current flowing through a long straight wire is 160 A. Determine the magnetic field due to a current at a distance of 4mm from the wire. A. 0.008 T B. 0.003 T C. 0.002 T D. 0.004 T 7)Which of the following statements is NOT correct? A. The tangent to the magnetic lines of force at every point gives the direction of the field B. The magnetic field lines are imaginary lines. C. The magnetic lines are continuous. D. The direction of the magnetic field outside a bar magnet points away from the South Pole of the magnet and toward the North Pole. 8)Which of the following is INCORRECT about the magnetic field B at a point? A. Its direction is that of the magnetic field B. It is also known as the magnetic induction strength C. Its direction is that of the magnetic force F D. It is also known as the magnetic flux density 9)The angle of declination (or variation) is A. the angle between the direction of magnetic South and the direction of geographical North at a particular point. B. the angle between the direction of magnetic North and the direction of geographical North at a particular point. C. the angle between the direction of magnetic South and the direction of geographical South at a particular time 10) the magnetic field at a distance of 5mm due to a current of 30A flowing through a lone straight wire. A. 6.00T B. 0.015T C. 1.05T D. 0.0012T 11)A block of semiconductor material is placed perpendicular to a magnetic field of intensity 0.1T. The Hall voltage across the block if 12.0mm width and thickness 4.0mm is 50mV. Calculate the current passing through the conductor? The number of charge carrier in the material is 8.0 × 10²⁰ A. 0.12 A B. 0.28 A C. 0.15 A D. 0.17 A 12) The pole-force law or law of poles states that A. unlike magnetic poles repel each other, and like magnetic poles attract each other. B. like magnetic poles repel each other, and unlike magnetic poles attract each other. C. force on the North pole is NOT equal to the force on the south pole. D. force on the North pole is equal to the force on the south 15)Which of the following in NOT a property of the magnetic lines of force? A. The direction of the magnetic field outside a bar magnet points away from the North pole of the magnet and toward the South pole. B. The closer together the field lines, the stronger the field. C. The magnetic lines are not always continuous. D. The magnetic field lines are imaginary lines 16)The wire carries a current I. At a distance of 6mm from the wire, the magnetic field strength is 0.004T. Find the magnitude of current I. A. 30A B. 60A C. 120A D. 150A 17)The angle of declination (or variation) is A. the angle between the direction of magnetic South and the direction of geographical North at a particular point. B. the angle between the direction of magnetic North and the direction of geographical North at a particular point. C. the angle between the direction of magnetic South and the direction of geographical South at a point 18)Calculate the magnetic field at a distance of 5mm due to a current of 30A flowing through a lone straight wire. A. 6.00T B. 0.015T C. 1.05T D. 0.0012T 19) A block of semiconductor material is placed perpendicular to a magnetic field of intensity 0.1T. The Hall voltage across the block if 12.0mm width and thickness 4.0mm is 50mV. Calculate the current passing through the conductor? The number of charge carrier in the material is 8.0 × 10²⁰ A. 0.12 A B. 0.28 A C. 0.15 A D. 0.17A

Here are the solutions to the magnetism questions: 1) At any point the magnetic field lines are in the direction of: Magnetic field lines indicate the direction of the magnetic field (B). The magnetic force (F) on a moving positive charge (q) is given by F = q(v × B), which means F is perpendicular to both v and B. Therefore, the magnetic field lines are not in the direction of the magnetic force or the velocity. The correct option is D. none of the above. 2) The units of magnetic dipole moments are: The magnetic dipole moment () is defined as the product of current ($I