- What is the exact speed of light in vacuum?
c = 299,792,458\ \text{m/s}A) 3 × 10⁶ m/s
A) 3 × 10⁶ m/s
B) 3 × 10⁷ m/s
C) 3 × 10⁸ m/s
D) 3 × 10⁹ m/s
- The symbol used for the speed of light is:
A) v
B) λ
C) c
D) f
- The speed of light in vacuum is approximately:
A) 300 km/s
B) 3,000 km/s
C) 30,000 km/s
D) 300,000 km/s
- Which scientist proved that light is an electromagnetic wave?
A) Isaac Newton
B) James Clerk Maxwell
C) Albert Einstein
D) Galileo Galilei
- Which equation relates the speed of light with wavelength and frequency?
c = f\lambdaA) F = ma
A) F = ma
B) E = mc²
C) c = fλ
D) p = mv
- Light travels fastest in:
A) Water
B) Glass
C) Air
D) Vacuum
- Which of the following travels at the speed of light in vacuum?
A) Sound waves
B) Electromagnetic waves
C) Water waves
D) Mechanical waves
- According to relativity, nothing can travel faster than:
A) Sound
B) Electricity
C) Gravity
D) Light
- Who proposed the theory of special relativity?
A) Maxwell
B) Einstein
C) Bohr
D) Tesla
- The famous equation relating mass and energy is:
E = mc^2A) p = mv
A) p = mv
B) V = IR
C) E = mc²
D) F = ma
- Light from the Sun reaches Earth in approximately:
A) 8 seconds
B) 8 minutes
C) 8 hours
D) 8 days
- The speed of light in water is:
A) Greater than in vacuum
B) Equal to vacuum
C) Less than in vacuum
D) Infinite
- A light-year is a unit of:
A) Time
B) Speed
C) Distance
D) Mass
- Which experiment failed to detect the luminiferous ether?
A) Rutherford experiment
B) Michelson–Morley experiment
C) Cavendish experiment
D) Young’s experiment
- Which wave does NOT require a medium to travel?
A) Sound wave
B) Water wave
C) Electromagnetic wave
D) Seismic wave
- What happens to light when it enters glass from air?
A) Speed increases
B) Speed decreases
C) Speed becomes zero
D) Speed remains unchanged
- Which quantity remains constant for all observers according to relativity?
A) Mass
B) Time
C) Speed of light
D) Velocity
- The refractive index is defined by:
n = \frac{c}{v}A) n = v/c
A) n = v/c
B) n = c/v
C) n = λf
D) n = mv
- Which phenomenon explains the blue glow in nuclear reactors?
A) Diffraction
B) Reflection
C) Cherenkov radiation
D) Polarization
- The nearest star to Earth after the Sun is:
A) Sirius
B) Polaris
C) Proxima Centauri
D) Betelgeuse
- Which type of radiation has the shortest wavelength?
A) Radio waves
B) Infrared waves
C) Visible light
D) Gamma rays
- What is the approximate distance traveled by light in one year?
1\ \text{light-year} \approx 9.46 \times 10^{15}\ \text{m}A) 9.46 × 10¹² m
A) 9.46 × 10¹² m
B) 9.46 × 10¹³ m
C) 9.46 × 10¹⁴ m
D) 9.46 × 10¹⁵ m
- Which property of light changes when it enters another medium?
A) Frequency
B) Energy
C) Speed
D) Charge
- Which scientist first estimated the speed of light using Jupiter’s moon Io?
A) Einstein
B) Newton
C) Ole Rømer
D) Maxwell
- Why can’t massive objects reach the speed of light?
A) They lose mass
B) Infinite energy would be required
C) Gravity stops them
D) Light pushes them back
