tis will help to your study easily and fast and it give you marks easily high

ISC Class 11 Physics - Units & Measurements
Formula Sheet
1. Speed
v = Distance / Time

2. Velocity
v = Displacement / Time

3. Acceleration
a = (v-u)/t

4. Density
ρ = m/V

5. Least Count (Vernier Calipers)
LC = 1 MSD − 1 VSD = (Value of 1 MSD)/(Number of Vernier Divisions)

6. Least Count (Screw Gauge)
LC = Pitch / Number of Circular Scale Divisions

7. Observed Reading
Observed Reading = Main Scale Reading + (Circular/Vernier Scale Reading × Least Count)

8. Correct Reading
Correct Reading = Observed Reading ± Zero Correction

9. Absolute Error
∆A = |Measured Value − True Value|

10. Mean Absolute Error
∆A■ = (Σ Absolute Errors)/n

11. Relative Error
Relative Error = ∆A■ / Mean Value

12. Percentage Error
% Error = (Relative Error) × 100

13. Fractional Error Rules
Addition/Subtraction: Absolute errors add.
Multiplication/Division: Fractional errors add.
Power n: Fractional error = n × fractional error.

14. Common Dimensional Formulae
Velocity = [LT^-1]
Acceleration = [LT^-2]
Force = [MLT^-2]
Momentum = [MLT^-1]
Work/Energy = [ML^2T^-2]
Power = [ML^2T^-3]
Pressure = [ML^-1T^-2]
Density = [ML^-3]