General Physics II — 2024 Past Questions

University of Ilorin PHY102: 119 questions.

Topics: Current, voltage and resistance, Capacitance, Magnetic fields, Lorentz force, Ohm's law and analysis of DC circuits, Biot-Savart and Ampère's laws, Energy in electric fields, Electric field and potential, Electric charge and its properties, Coulomb's law and superposition, Gauss's law

1. A bar magnet is divided into two pieces. Which of the following statements is true?
   1. The bar magnet is demagnetized
   2. The magnetic field of each separated piece becomes stronger
   3. The magnetic poles are separated
   4. Two new bar magnets are created
2. A bar magnet is divided into two pieces. Which statement is true about the force between the broken pieces if they face each other with a small separation?
   1. There is an electric repulsive force between the broken pieces
   2. There is a magnetic repulsive force between the broken pieces
   3. There is a magnetic attractive force between the broken pieces
   4. There is no force between the broken pieces since they are demagnetized
3. Which of the following statements about the magnetic field of a single bar magnet is correct? (Figure question converted to text.)
   1. Outside the magnet, field lines leave the north pole and enter the south pole, forming closed loops
   2. Outside the magnet, field lines leave the south pole and enter the north pole
   3. Field lines start at the north pole and end at the south pole without forming closed loops
   4. Field lines are straight and parallel to the magnet everywhere
4. A DC current produces a/an:
   1. Magnetic field
   2. Electric field
   3. Gravitational field
   4. Electromagnetic field
5. An electric current flows into the page. What is the direction of the magnetic field?
   1. To the bottom of the page
   2. To the top of the page
   3. Clockwise
   4. Counter-clockwise
6. A current-carrying wire is perpendicular to the page and its magnetic field circles it counter-clockwise. What is the direction of the current?
   1. Into the page
   2. Out of the page
   3. Clockwise
   4. Counter-clockwise
7. A vertical wire carries an electric current into the page. What is the direction of the magnetic field at point P located south of the wire?
   1. West
   2. North
   3. East
   4. South
8. A vertical wire carries an electric current out of the page. What is the direction of the magnetic field at point P located west of the wire?
   1. West
   2. North
   3. East
   4. South
9. A circular loop carries a current in the counter-clockwise direction. Which statement describes the magnetic field of the loop? (Figure question converted to text.)
   1. Out of the page inside the loop and into the page outside the loop
   2. Into the page inside the loop and out of the page outside the loop
   3. Out of the page both inside and outside the loop
   4. Into the page both inside and outside the loop
10. A straight long wire carries an electric current to the right in a uniform magnetic field directed into the page. What is the direction of the magnetic force on the current?
    1. Left
    2. Right
    3. To the bottom of the page
    4. To the top of the page
11. A straight long wire carries an electric current to the top of the page in a uniform magnetic field directed out of the page. What is the direction of the magnetic force on the current?
    1. Left
    2. Right
    3. To the bottom of the page
    4. To the top of the page
12. A straight long wire carries an electric current out of the page in a uniform magnetic field directed into the page. What is the direction of the magnetic force on the current?
    1. Left
    2. To the bottom of the page
    3. To the top of the page
    4. There is no magnetic force on the current
13. A positive charge moving to the right with constant velocity enters a region of uniform magnetic field pointing out of the page. What is the direction of the magnetic force on the charge?
    1. Left
    2. Right
    3. To the bottom of the page
    4. To the top of the page
14. A negative charge moving upward with constant velocity enters a region of uniform magnetic field pointing out of the page. What is the direction of the magnetic force on the charge?
    1. Left
    2. Right
    3. To the bottom of the page
    4. To the top of the page
15. A negative charge moving to the right with constant velocity enters a region of uniform magnetic field pointing into the page. What is the direction of the magnetic force on the charge?
    1. Left
    2. Right
    3. To the bottom of the page
    4. To the top of the page
16. A positive charge moving upward with constant velocity enters a region of uniform magnetic field pointing into the page. What is the direction of the magnetic force on the charge?
    1. Left
    2. Right
    3. To the bottom of the page
    4. To the top of the page
17. A positive charge moving upward with constant velocity enters a region of uniform magnetic field pointing to the top of the page. What is the direction of the magnetic force on the charge?
    1. Left
    2. To the bottom of the page
    3. To the top of the page
    4. There is no magnetic force on the charge
18. A positive charge placed above a long wire moves parallel to the current in the wire (both to the right). What is the direction of the magnetic force on the charge?
    1. Left
    2. Right
    3. To the bottom of the page
    4. To the top of the page
19. A negative charge to the right of a vertical wire (current upward) moves away from the wire, to the right. What is the direction of the magnetic force on the charge?
    1. Left
    2. Right
    3. To the bottom of the page
    4. To the top of the page
20. A vertical wire carries an electric current into the page. An electron approaches the wire from the east. What is the direction of the magnetic force on the electron?
    1. West
    2. North
    3. South
    4. Into the page
21. What is the SI unit of electric charge?
    1. Coulomb
    2. Volt
    3. Ampere
    4. Ohm
22. Which law states that the force between two charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them?
    1. Ohm's Law
    2. Coulomb's Law
    3. Faraday's Law
    4. Gauss's Law
23. If two charges q₁ = +3 μC and q₂ = −3 μC are placed 2 m apart, what is the magnitude of the force between them? (Use k = 9 × 10⁹ N m²/C²)
    1. 2.7 × 10⁻² N
    2. 4.05 × 10⁻² N
    3. 3.6 × 10⁻² N
    4. 2.03 × 10⁻² N
24. An electric field is defined as:
    1. The force per unit charge
    2. The potential energy per unit charge
    3. The current per unit charge
    4. The voltage per unit distance
25. The electric field inside a conductor in electrostatic equilibrium is:
    1. Zero
    2. Constant
    3. Equal to the electric potential
    4. Equal to the charge density
26. Which of the following describes the direction of an electric field?
    1. From positive to negative charge
    2. From negative to positive charge
    3. Circular around the charge
    4. Perpendicular to the charge
27. Two point charges q₁ and q₂ are placed 5 cm apart in a vacuum and repel each other with a force of 9 N. If the distance is doubled, what will be the force between them?
    1. 2.25 N
    2. 4.5 N
    3. 1.125 N
    4. 9 N
28. Which of the following is true about the electric potential at a point?
    1. It is the work done in bringing a unit charge from infinity to that point
    2. It is the force experienced by a unit charge at that point
    3. It is the current flowing through that point
    4. It is the power dissipated at that point
29. The potential difference between two points in an electric field is 12 V. If a charge of 2 C is moved between these points, what is the work done?
    1. 6 J
    2. 12 J
    3. 24 J
    4. 48 J
30. Which of the following materials would be considered an insulator?
    1. Copper
    2. Glass
    3. Aluminum
    4. Silver
31. In an electric field, the electric flux through a closed surface is proportional to:
    1. The charge enclosed by the surface
    2. The distance between the charges
    3. The surface area
    4. The resistance of the surface
32. What is the potential energy of a charge q = 5 C in a uniform electric field E = 10 N/C at a distance d = 2 m (from the reference point)?
    1. 10 J
    2. 20 J
    3. 100 J
    4. 50 J
33. The force on a charge in a uniform electric field is:
    1. Proportional to the square of the charge
    2. Inversely proportional to the charge
    3. Proportional to the charge and the electric field strength
    4. Independent of the charge
34. If a positively charged object is brought close to a neutral conductor and no contact is made, what will happen to the charges in the conductor?
    1. The conductor will gain a net positive charge
    2. The conductor will gain a net negative charge
    3. The conductor will be repelled by the object
    4. Charges in the conductor will rearrange
35. Which of the following best describes the concept of capacitance?
    1. The ability to store charge
    2. The resistance to the flow of current
    3. The potential difference between two points
    4. The current flowing through a circuit
36. What is the capacitance of a parallel plate capacitor with a plate area of 2 m² and a separation of 1 mm, with air as the dielectric? (Use ε₀ = 8.85 × 10⁻¹² F/m)
    1. 17.7 nF
    2. 22.2 nF
    3. 35.4 nF
    4. 44.3 nF
37. If a capacitor is connected to a battery and then disconnected, the charge on the capacitor will:
    1. Remain the same
    2. Decrease rapidly
    3. Increase steadily
    4. Discharge completely
38. In electrostatics, the potential energy of a system of charges is:
    1. The work done to assemble the charges from infinity to their current positions
    2. The kinetic energy of the charges
    3. The heat produced by the charges
    4. The current produced by the charges
39. The work required to move a 5 C charge against an electric field over a distance of 10 m with a field strength of 15 N/C is:
    1. 750 J
    2. 500 J
    3. 1000 J
    4. 1500 J
40. What happens to the electric field strength of a point charge if the distance from it is halved?
    1. It doubles
    2. It quadruples
    3. It remains the same
    4. It halves
41. What is the SI unit of capacitance?
    1. Farad (F)
    2. Henry (H)
    3. Coulomb (C)
    4. Volt (V)
42. Which of the following describes the capacitance of a capacitor?
    1. The ratio of the charge on each conductor to the potential difference between them
    2. The product of charge and potential difference
    3. The energy stored in the capacitor
    4. The resistance of the capacitor
43. The capacitance of a parallel plate capacitor depends on:
    1. The area of the plates and the distance between them
    2. The charge on the plates and the distance between them
    3. The voltage applied and the charge stored
    4. The colour of the plates
44. If the distance between the plates of a capacitor is halved, the capacitance will:
    1. Double
    2. Halve
    3. Remain the same
    4. Quadruple
45. Which of the following increases the capacitance of a capacitor?
    1. Increasing the area of the plates
    2. Decreasing the distance between the plates
    3. Adding a dielectric material between the plates
    4. All of the above
46. A capacitor is charged to a potential difference of 10 V and stores a charge of 5 C. What is its capacitance?
    1. 0.5 F
    2. 2 F
    3. 5 F
    4. 0.2 F
47. In a series combination of capacitors, the equivalent capacitance is:
    1. The sum of the individual capacitances
    2. Less than any of the individual capacitances
    3. The product of the individual capacitances
    4. Equal to the largest individual capacitance
48. In a parallel combination of capacitors, the equivalent capacitance is:
    1. The sum of the individual capacitances
    2. Less than the smallest capacitance
    3. Equal to the smallest capacitance
    4. Equal to the average of the capacitances
49. A capacitor stores energy in the form of:
    1. Magnetic field energy
    2. Kinetic energy
    3. Electric potential energy (in the electric field between the plates)
    4. Thermal energy
50. If the voltage across a capacitor is doubled, the energy stored in the capacitor:
    1. Remains the same
    2. Doubles
    3. Quadruples
    4. Halves
51. A 2 F capacitor is connected in series with a 4 F capacitor. What is the equivalent capacitance of the combination?
    1. 6 F
    2. 1.33 F
    3. 0.67 F
    4. 2.67 F
52. A dielectric material is inserted between the plates of a capacitor. How does this affect the capacitance?
    1. Increases it
    2. Decreases it
    3. Has no effect
    4. Reduces it to zero
53. The dielectric constant k is defined as:
    1. The ratio of the capacitance with the dielectric to the capacitance without the dielectric
    2. The ratio of charge to voltage in a capacitor
    3. The product of charge and potential difference
    4. The resistance of the dielectric material
54. Two capacitors, one of 3 F and the other of 6 F, are connected in parallel. What is the total capacitance?
    1. 2 F
    2. 9 F
    3. 18 F
    4. 1 F
55. If a 5 F capacitor is charged to 20 V, how much charge is stored on the capacitor?
    1. 25 C
    2. 100 C
    3. 10 C
    4. 0.25 C
56. Which of the following is true about the potential difference across capacitors in parallel?
    1. It is the same across all capacitors
    2. It is different for each capacitor
    3. It depends on the individual capacitances
    4. It is zero
57. The potential energy stored in a 2 F capacitor charged to 5 V is:
    1. 25 J
    2. 50 J
    3. 5 J
    4. 12.5 J
58. When the distance between the plates of a capacitor is doubled, the capacitance:
    1. Doubles
    2. Halves
    3. Quadruples
    4. Remains the same
59. The energy stored in a capacitor can be increased by:
    1. Increasing the capacitance
    2. Increasing the voltage across the plates
    3. Adding a dielectric material
    4. All of the above
60. A parallel plate capacitor with a capacitance of 8 F is charged to 12 V and then disconnected from the battery. What happens to the voltage across the plates if the distance between the plates is increased while the charge stays constant?
    1. The voltage decreases
    2. The voltage increases
    3. The voltage remains the same
    4. The voltage becomes zero
61. What is the SI unit of electrical resistance?
    1. Ohm (Ω)
    2. Volt (V)
    3. Ampere (A)
    4. Watt (W)
62. Ohm's Law states that the current through a conductor between two points is directly proportional to the:
    1. Resistance
    2. Voltage
    3. Power
    4. Charge
63. If the resistance of a conductor is 10 Ω and a current of 2 A flows through it, what is the voltage across the conductor?
    1. 5 V
    2. 10 V
    3. 20 V
    4. 40 V
64. Which of the following materials is typically a good conductor of electricity?
    1. Copper
    2. Rubber
    3. Glass
    4. Wood
65. The total resistance in a series circuit is:
    1. Equal to the sum of the individual resistances
    2. Less than the smallest resistance
    3. The product of the individual resistances
    4. Equal to the largest resistance
66. In a parallel circuit, the equivalent resistance is:
    1. Equal to the sum of the individual resistances
    2. Less than the smallest resistance in the circuit
    3. Equal to the largest resistance
    4. The product of the resistances
67. A resistor of 5 Ω is connected in series with another resistor of 10 Ω. What is the total resistance of the circuit?
    1. 15 Ω
    2. 5 Ω
    3. 10 Ω
    4. 2 Ω
68. If three resistors of 2 Ω, 4 Ω and 6 Ω are connected in parallel, what is the equivalent resistance?
    1. 12 Ω
    2. 1 Ω
    3. 7.2 Ω
    4. 1.09 Ω
69. Which of the following factors does NOT affect the resistance of a wire?
    1. Length of the wire
    2. Cross-sectional area of the wire
    3. Temperature of the wire
    4. Colour of the wire
70. The resistance of a conductor increases with:
    1. An increase in temperature
    2. A decrease in temperature
    3. A decrease in length
    4. A decrease in the resistivity of the material
71. The resistivity of a material is defined as:
    1. The resistance per unit length
    2. The resistance per unit area
    3. The resistance per unit length and cross-sectional area
    4. The resistance per unit volume
72. A wire has a resistance of 8 Ω. If the length of the wire is doubled while keeping the material and temperature constant, the new resistance will be:
    1. 4 Ω
    2. 8 Ω
    3. 16 Ω
    4. 32 Ω
73. If the cross-sectional area of a wire is tripled, what happens to its resistance?
    1. It triples
    2. It doubles
    3. It is reduced to one-third
    4. It remains the same
74. A circuit consists of a 12 V battery and a resistor of 3 Ω. What is the current flowing through the circuit?
    1. 4 A
    2. 3 A
    3. 36 A
    4. 1 A
75. Which of the following is true about the resistivity of a material?
    1. It is independent of the material's dimensions
    2. It decreases with an increase in length
    3. It increases with an increase in cross-sectional area
    4. It is the same for all materials
76. A wire has a resistance of 5 Ω at 20 °C. If the temperature is increased to 100 °C, the resistance increases to 7 Ω. What is the temperature coefficient of resistance?
    1. 0.005/°C
    2. 0.01/°C
    3. 0.05/°C
    4. 0.1/°C
77. The power dissipated by a resistor can be calculated using which of the following formulas?
    1. P = IV
    2. P = I²R
    3. P = V²/R
    4. All of the above
78. If the voltage across a 10 Ω resistor is 50 V, what is the power dissipated by the resistor?
    1. 5 W
    2. 250 W
    3. 500 W
    4. 25 W
79. Which of the following describes the behaviour of a superconductor?
    1. It has infinite resistance at low temperatures
    2. It has zero resistance at very low temperatures
    3. It increases resistance with increasing current
    4. It has high resistance at room temperature
80. If two resistors of 4 Ω and 6 Ω are connected in parallel, what is the total resistance?
    1. 2.4 Ω
    2. 5 Ω
    3. 10 Ω
    4. 3.33 Ω
81. Which of the following is a ferromagnetic material?
    1. Copper
    2. Aluminium
    3. Iron
    4. Plastic
82. The magnetic field lines around a straight current-carrying conductor are:
    1. Straight lines
    2. Circular
    3. Elliptical
    4. Parabolic
83. According to Ampère's Circuital Law, the magnetic field around a current-carrying wire is proportional to:
    1. The length of the wire
    2. The square of the current
    3. The current
    4. The square of the magnetic field
84. The force on a charged particle moving in a magnetic field is maximum when the particle moves:
    1. Parallel to the magnetic field
    2. Perpendicular to the magnetic field
    3. At an angle of 45° to the magnetic field
    4. Opposite to the magnetic field
85. What is the magnetic flux through a loop of area 0.1 m² in a uniform magnetic field of 0.5 T perpendicular to the loop?
    1. 0.05 Wb
    2. 0.5 Wb
    3. 0.1 Wb
    4. 5 Wb
86. Which of the following laws is used to determine the direction of induced current in a loop?
    1. Ohm's Law
    2. Faraday's Law
    3. Lenz's Law
    4. Coulomb's Law
87. A current-carrying loop placed in a magnetic field experiences a torque. This principle is the basis of:
    1. Electric motor
    2. Generator
    3. Transformer
    4. Capacitor
88. If the magnetic field strength inside a long solenoid is 0.2 T and the current is 5 A, what is the length of the solenoid with 100 turns? (μ₀ = 4π × 10⁻⁷ T m/A)
    1. 0.0314 m
    2. 0.00314 m
    3. 0.0628 m
    4. 0.314 m
89. The Earth's magnetic field is believed to be caused by:
    1. The movement of molten iron in its outer core
    2. The rotation of the Earth
    3. The atmosphere
    4. The gravitational pull of the moon
90. The unit of magnetic flux is:
    1. Tesla
    2. Weber
    3. Ampere
    4. Joule
91. If the length of a magnetic material is doubled, its magnetic moment:
    1. Doubles
    2. Halves
    3. Remains the same
    4. Becomes zero
92. What is the force on a 2 m long wire carrying a current of 3 A placed in a magnetic field of 0.5 T perpendicular to the wire?
    1. 3 N
    2. 6 N
    3. 9 N
    4. 12 N
93. Which of the following devices uses the principle of electromagnetic induction?
    1. Transformer
    2. Galvanometer
    3. Ammeter
    4. Voltmeter
94. The magnetic dipole moment of a current loop is given by which of the following expressions?
    1. I/A
    2. IA
    3. I²A
    4. I/A²
95. Which law states that the induced EMF in a circuit is directly proportional to the rate of change of magnetic flux through the circuit?
    1. Lenz's Law
    2. Faraday's Law
    3. Biot-Savart Law
    4. Ampère's Law
96. A magnetic field exerts a force on a moving charge. This force is called:
    1. Electromagnetic force
    2. Magnetic force
    3. Electrostatic force
    4. Nuclear force
97. A bar magnet is cut into two equal halves. The magnetic moment of each piece is:
    1. Halved
    2. Doubled
    3. Unchanged
    4. Zero
98. The angle of dip at the magnetic equator is:
    1. 0°
    2. 45°
    3. 90°
    4. 180°
99. Two parallel wires carry currents of 5 A and 10 A in opposite directions. If the wires are 0.1 m apart, what is the force per unit length between the wires? (μ₀ = 4π × 10⁻⁷ T m/A)
    1. 1 × 10⁻⁴ N/m (repulsive)
    2. 1 × 10⁻⁴ N/m (attractive)
    3. 1 × 10⁻⁵ N/m (repulsive)
    4. 1 × 10⁻⁵ N/m (attractive)
100. In an A.C. circuit, the voltage and current are generally:
     1. In phase
     2. Out of phase
     3. Perpendicular to each other
     4. Always zero

Register free to unlock all 119 questions with answers and explanations