Electromagnetism MCQs January 8, 2026July 12, 2024 by u930973931_answers 50 min Score: 0 Attempted: 0/50 Subscribe 1. What property of a material determines its ability to conduct electricity? (A) Density (B) Resistivity (C) Hardness (D) Elasticity 2. Which law describes the magnetic field produced by a current-carrying conductor? (A) Gauss’s Law (B) Faraday’s Law (C) Ampère’s Law (D) Ohm’s Law 3. Which of the following devices is used to measure current in a circuit? (A) Voltmeter (B) Ammeter (C) Galvanometer (D) Ohmmeter 4. The phenomenon of electromagnetic induction is associated with which scientist’s discoveries? (A) Michael Faraday (B) Albert Einstein (C) Nikola Tesla (D) Thomas Edison 5. According to Lenz’s Law, the direction of an induced current in a conductor is such that it: (A) Creates a magnetic field opposing the change in magnetic flux (B) Creates a magnetic field aiding the change in magnetic flux (C) Does not affect the magnetic flux (D) Creates a current in the opposite direction of the magnetic flux 6. Which of the following is an example of a non-contact force in electromagnetism? (A) Tension in a string (B) Friction between surfaces (C) Magnetic force between two magnets (D) Normal force between two surfaces 7. What does the term ‘electromagnetic spectrum’ refer to? (A) Range of all possible frequencies of electromagnetic radiation (B) Range of colors visible to the human eye (C) Range of frequencies used in telecommunications (D) Range of frequencies used in radar technology 8. Which electromagnetic wave has the shortest wavelength? (A) Radio waves (B) Microwaves (C) X-rays (D) Gamma rays 9. What is the SI unit of magnetic flux? (A) Weber (B) Tesla (C) Gauss (D) Henry 10. The process of converting mechanical energy into electrical energy using a magnetic field is the principle behind: (A) Electric motor (B) Transformer (C) Dynamo (D) Capacitor 11. The ability of a material to become magnetized temporarily when placed in an external magnetic field is known as: (A) Paramagnetism (B) Diamagnetism (C) Ferromagnetism (D) Electromagnetism 12. Which law states that the magnetic flux through a closed surface is zero? (A) Gauss’s Law for Magnetism (B) Faraday’s Law of Induction (C) Ampère’s Law (D) Kirchhoff’s Law 13. What is the SI unit of magnetic field strength? (A) Tesla (B) Weber (C) Coulomb (D) Henry 14. Which of the following materials is typically used as a core in an electromagnet? (A) Copper (B) Aluminum (C) Iron (D) Silver 15. What does an electric generator convert mechanical energy into? (A) Heat energy (B) Electrical energy (C) Magnetic energy (D) Potential energy 16. Which of the following laws describes the force between two electric charges? (A) Newton’s Law (B) Coulomb’s Law (C) Ohm’s Law (D) Kepler’s Law 17. What is the relationship between current (I), voltage (V), and resistance (R) in an electrical circuit according to Ohm’s Law? (A) I = V / R (B) V = I * R (C) R = V / I (D) I = R / V 18. Which type of electromagnetic wave is used for communication with satellites? (A) Microwaves (B) Infrared waves (C) X-rays (D) Radio waves 19. The electric field strength is measured in which of the following units? (A) Volts (B) Watts (C) Ohms (D) Newtons per Coulomb 20. Which of the following is NOT a component of an AC circuit? (A) Capacitor (B) Inductor (C) Battery (D) Diode 21. What is the main difference between AC (Alternating Current) and DC (Direct Current)? (A) Direction of flow of electrons (B) Magnitude of current (C) Voltage level (D) Frequency of current reversal 22. Which law states that the induced electromotive force (emf) in any closed circuit is equal to the rate of change of magnetic flux through the circuit? (A) Gauss’s Law (B) Ohm’s Law (C) Faraday’s Law (D) Lenz’s Law 23. Which of the following effects is NOT explained by classical electromagnetism? (A) Photoelectric effect (B) Faraday’s Law of Induction (C) Maxwell’s equations (D) Ampère’s Law 24. Which type of material has the highest permeability? (A) Diamagnetic material (B) Paramagnetic material (C) Ferromagnetic material (D) Non-magnetic material 25. What is the SI unit of capacitance? (A) Ohm (B) Farad (C) Weber (D) Tesla 26. Which device is used to store electric charge? (A) Resistor (B) Capacitor (C) Inductor (D) Transformer 27. Which of the following electromagnetic waves is used in medical imaging to visualize bones and tissues? (A) Ultraviolet rays (B) X-rays (C) Gamma rays (D) Infrared waves 28. What phenomenon explains why a compass needle points north when placed near a current-carrying wire? (A) Ampère’s Law (B) Faraday’s Law (C) Lenz’s Law (D) Right-hand rule 29. Which law states that the electric flux through a closed surface is proportional to the electric charge enclosed by the surface? (A) Gauss’s Law (B) Ohm’s Law (C) Coulomb’s Law (D) Ampère’s Law 30. What property of an electric circuit does a voltmeter measure? (A) Resistance (B) Voltage (C) Current (D) Power 31. In a transformer, which coil is connected to the AC power source? (A) Primary coil (B) Secondary coil (C) Tertiary coil (D) Both primary and secondary coils 32. Which type of electromagnetic wave is used in remote controls for TVs and other appliances? (A) Infrared waves (B) Radio waves (C) Microwaves (D) Ultraviolet rays 33. The potential difference between two points in an electric circuit is commonly known as: (A) Current (B) Resistance (C) Voltage (D) Power 34. Which of the following devices converts electrical energy into mechanical energy? (A) Transformer (B) Capacitor (C) Inductor (D) Electric motor 35. Which electromagnetic wave has a frequency just below visible light? (A) Infrared waves (B) Ultraviolet rays (C) X-rays (D) Gamma rays 36. What phenomenon allows a material to retain its magnetization after the external magnetic field is removed? (A) Paramagnetism (B) Diamagnetism (C) Ferromagnetism (D) Electromagnetism 37. Which law states that the total electric flux through a closed surface is equal to the net electric charge enclosed by the surface divided by the permittivity of free space? (A) Gauss’s Law (B) Ohm’s Law (C) Coulomb’s Law (D) Ampère’s Law 38. The rate of doing work or the rate at which energy is transferred is known as: (A) Voltage (B) Power (C) Current (D) Energy 39. Which electromagnetic wave is used for cooking food in a microwave oven? (A) Infrared waves (B) Microwaves (C) Radio waves (D) X-rays 40. Which of the following is a property of an ideal conductor? (A) High resistance (B) Low resistance (C) High capacitance (D) Low capacitance 41. What is the SI unit of magnetic flux density? (A) Weber (B) Tesla (C) Coulomb (D) Henry 42. Which electromagnetic wave is used in radar systems to detect the speed of moving objects? (A) X-rays (B) Radio waves (C) Infrared waves (D) Ultraviolet rays 43. The process of charging a neutral object by bringing it near a charged object without direct contact is an example of: (A) Induction (B) Conduction (C) Polarization (D) Electrification 44. Which law relates the magnetic field around a closed loop to the electric current passing through the loop? (A) Gauss’s Law (B) Ampère’s Law (C) Faraday’s Law (D) Lenz’s Law 45. Which electromagnetic wave is used in fiber optics for communication? (A) Radio waves (B) Infrared waves (C) X-rays (D) Ultraviolet rays 46. Which of the following is a characteristic of superconductors at low temperatures? (A) High resistance (B) Low resistance (C) High capacitance (D) Low capacitance 47. The property of a material to oppose the flow of electric current is known as: (A) Conductance (B) Resistance (C) Capacitance (D) Inductance 48. Which of the following electromagnetic waves has the longest wavelength? (A) Gamma rays (B) X-rays (C) Radio waves (D) Ultraviolet rays 49. Which electromagnetic wave is used in astronomy to observe stars and galaxies? (A) Infrared waves (B) Microwaves (C) X-rays (D) Gamma rays 50. What is the unit of inductance in an electrical circuit? (A) Ohm (B) Farad (C) Weber (D) Henry