Electric circuits magnetism light reflection refraction and lenses. - Question Bank

1. In a parallel circuit, if one branch is open, the current will:
A) Stop flowing in all branches
B) Continue flowing in the other branches
C) Increase in the other branches
D) Decrease in the other branches
2. A device that converts electrical energy into light energy is a:
A) Heater
B) Motor
C) Light bulb
D) Speaker
3. Which phenomenon is responsible for the formation of a rainbow?
A) Reflection only
B) Refraction only
C) Dispersion and total internal reflection
D) Diffraction
4. The process by which a neutral object becomes electrically charged is called:
A) Conduction
B) Induction
C) Friction
D) All of the above
5. What is the direction of the magnetic field lines around a bar magnet?
A) From South to North outside the magnet
B) From North to South outside the magnet
C) They do not form closed loops
D) They start from the center and go outwards
6. The SI unit of electric power is:
A) Joule
B) Watt
C) Volt
D) Ampere
7. The ability of a material to resist the flow of electric current is called:
A) Conductivity
B) Resistivity
C) Permittivity
D) Permeability
8. What type of mirror is used as a rearview mirror in vehicles?
A) Plane mirror
B) Concave mirror
C) Convex mirror
D) Parabolic mirror
9. The phenomenon of light from a source spreading out after passing through a narrow slit is called:
A) Interference
B) Diffraction
C) Polarization
D) Refraction
10. What is the device used to detect the presence and direction of electric current in a circuit?
A) Ammeter
B) Voltmeter
C) Galvanometer
D) Ohmmeter
11. The force experienced by a current-carrying conductor placed in a magnetic field is given by:
A) F = BIL sin θ
B) F = qvB
C) V = IR
D) E = mc²
12. What is the magnetic field inside a long, straight solenoid approximately:
A) Zero
B) Uniform
C) Variable
D) Zero at the center and increases outwards
13. If the resistance in a circuit is doubled, and the voltage remains constant, the current will:
A) Double
B) Halve
C) Remain the same
D) Become zero
14. Which of the following is an insulator?
A) Gold
B) Silver
C) Wood
D) Copper
15. What is the unit of power of a lens?
A) Watt
B) Joule
C) Diopter
D) Ohm
16. When light travels from a rarer medium to a denser medium, it bends:
A) Away from the normal
B) Towards the normal
C) Parallel to the normal
D) Does not bend
17. A convex lens is also known as a(n):
A) Diverging lens
B) Converging lens
C) Spherical lens
D) Cylindrical lens
18. The phenomenon of light scattering by particles in the atmosphere causing the blue color of the sky is an example of:
A) Reflection
B) Refraction
C) Dispersion
D) Rayleigh scattering
19. Electromagnets are typically made using:
A) Hard iron
B) Soft iron
C) Steel
D) Aluminum
20. Which law describes the direction of the induced current in a conductor moving in a magnetic field?
A) Lenz's Law
B) Faraday's Law
C) Ampere's Law
D) Biot-Savart Law
21. The SI unit of magnetic flux is:
A) Tesla
B) Weber
C) Gauss
D) Ampere
22. What is the potential difference across a resistor of 10 ohms carrying a current of 2 amperes?
A) 5 Volts
B) 20 Volts
C) 0.5 Volts
D) 12 Volts
23. Which of the following materials is a good conductor of electricity?
A) Rubber
B) Glass
C) Copper
D) Plastic
24. What is the power of a lens with a focal length of -2 meters?
A) 0.5 D
B) -0.5 D
C) 2 D
D) -2 D
25. The refractive index of a medium is defined as the ratio of the speed of light in vacuum to the:
A) Speed of light in the medium
B) Speed of sound in the medium
C) Speed of light in air
D) Speed of light in glass
26. Which of the following is a characteristic of the image formed by a convex mirror?
A) Real, magnified, and inverted
B) Virtual, diminished, and erect
C) Real, diminished, and erect
D) Virtual, magnified, and inverted
27. The image formed by a plane mirror is always:
A) Real and inverted
B) Virtual and erect
C) Real and erect
D) Virtual and inverted
28. What is the phenomenon of splitting of white light into its constituent colors called?
A) Refraction
B) Reflection
C) Dispersion
D) Diffraction
29. The direction of the magnetic field produced by a current-carrying solenoid is determined by:
A) Ohm's Law
B) Fleming's Right-Hand Rule
C) Coulomb's Law
D) Snell's Law
30. A device that converts mechanical energy into electrical energy using the principle of electromagnetic induction is a:
A) Motor
B) Generator
C) Dynamo
D) Both B and C
31. The magnetic field lines around a straight current-carrying wire are:
A) Straight lines
B) Circular
C) Elliptical
D) Spiral
32. In a parallel circuit, the voltage across each component is:
A) Different
B) The same
C) Zero
D) Variable
33. What happens to the total resistance in a series circuit when another resistor is added?
A) It decreases
B) It increases
C) It remains the same
D) It becomes zero
34. A circuit where the components are connected end-to-end in a single path is called a(n):
A) Parallel circuit
B) Series circuit
C) Combination circuit
D) Open circuit
35. The SI unit of electrical resistance is:
A) Siemens
B) Farad
C) Henry
D) Ohm
36. Which color of visible light has the shortest wavelength?
A) Red
B) Violet
C) Green
D) Blue
37. What causes dispersion of white light into its constituent colors when it passes through a prism?
A) Reflection
B) Refraction
C) Diffraction
D) Polarization
38. The focal length of a lens is the distance between:
A) The optical center and the pole
B) The optical center and the principal focus
C) The pole and the principal focus
D) The center of curvature and the pole
39. A concave lens always forms an image that is:
A) Real, inverted, and magnified
B) Virtual, erect, and diminished
C) Real, erect, and diminished
D) Virtual, inverted, and magnified
40. Which type of lens is thicker at the center and thinner at the edges, and converges parallel rays of light?
A) Concave lens
B) Convex lens
C) Plano-concave lens
D) Plano-convex lens
41. What is the phenomenon where light bounces off a surface?
A) Refraction
B) Diffraction
C) Reflection
D) Interference
42. The law that describes the relationship between the angle of incidence, angle of refraction, and the refractive indices of the two media is:
A) Law of Reflection
B) Snell's Law
C) Huygens' Principle
D) Doppler Effect
43. What is the bending of light as it passes from one medium to another called?
A) Reflection
B) Diffraction
C) Refraction
D) Dispersion
44. Which type of magnet retains its magnetism for a long time and is difficult to demagnetize?
A) Temporary magnet
B) Electromagnet
C) Permanent magnet
D) Induced magnet
45. The phenomenon of inducing an electromotive force (EMF) in a circuit due to a change in magnetic flux is called:
A) Electromagnetic induction
B) Electrostatic induction
C) Magnetic resonance
D) Magnetic saturation
46. What is the SI unit of magnetic field strength?
A) Ampere per meter
B) Tesla
C) Gauss
D) Weber
47. A device that converts electrical energy into mechanical energy is known as:
A) Generator
B) Motor
C) Transformer
D) Resistor
48. What is the opposition to the flow of electric current called?
A) Conductance
B) Resistance
C) Capacitance
D) Inductance
49. Which law states that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance between them?
A) Joule's Law
B) Faraday's Law
C) Ohm's Law
D) Ampere's Law
50. What is the unit of electric current?
A) Volt
B) Ohm
C) Ampere
D) Watt