“What you see depends on how fast you’re moving.”
Einstein’s Special Theory of Relativity (1905) is like saying: “Time, length, and mass aren’t absolute. They flex when you move super fast.”
Imagine taking a selfie in a moving train — for you it's sharp, but for someone outside it’s blurry AF.
Where:
Key Idea: Astronauts age slower in a spaceship traveling close to light speed. (Interstellar movie was based on this!)
PYQ Type: Formula match or conceptual
Where:
Your moving bike looks a tiny bit shorter to a friend standing still. (Not visible in real life — but physics says so!)
PYQ Type: Formula MCQ
Meaning: Mass can convert into energy, and energy has mass.
That nuclear bomb from Oppenheimer trailer? That’s pure E = mc² in action.
PYQ Type: AAI ATC Favorite: Unit/concept MCQ
Year Question Type
2021: Mass-energy formula
2022: Time dilation formula match
2023: Unit of c (speed of light)
| Concept | Formula |
|---|---|
| Time Dilation | \( \Delta t = \frac{\Delta t_0}{\sqrt{1 - \frac{v^2}{c^2}}} \) |
| Length Contraction | \( L = L_0 \sqrt{1 - \frac{v^2}{c^2}} \) |
| Mass-Energy | \( E = mc^2 \) |
| Concept | GenZ Example |
|---|---|
| Time runs slow for fast movers | Interstellar movie scene |
| Moving objects shrink | Moving bullet’s length shorter for bystander |
| Mass turns to energy | Nuclear explosion from 1 gm of matter releasing megawatts |
Q1. Time dilation means:
a) Moving clocks run faster
b) Moving clocks run slower
c) Length increases
d) None
Ans: b
Q2. Length contraction occurs when:
a) At rest
b) Moving close to light speed
c) Zero speed
d) None
Ans: b
Q3. Mass-energy relation is:
a) \( E = mc^2 \)
b) \( F = ma \)
c) \( V = IR \)
d) \( q = mc\Delta T \)
Ans: a
Q4. Which constant appears in relativity formulas?
a) g
b) h
c) c
d) R
Ans: c
Q5. If v = 0, then time dilation factor is:
a) 1
b) 0
c) \(\infty\)
d) None
Ans: a
Q6. Relativity affects:
a) Only fast-moving objects
b) Slow-moving objects
c) Stationary objects
d) None
Ans: a
Q7. Length contraction is observed:
a) Along direction of motion
b) Perpendicular to motion
c) Upward
d) None
Ans: a
Q8. SI unit of speed of light c is:
a) m/s
b) J
c) Wb
d) Tesla
Ans: a
Q9. Nuclear reactions release energy because of:
a) Mass gain
b) Mass loss converted to energy
c) No change
d) None
Ans: b
Q10. Time slows down for:
a) Rest observers
b) Faster moving observers
c) Stationary walls
d) Batteries
Ans: b