CLASS 11 PHYSICS
Complete Coursebook • Concepts • Derivations • Solved Numericals • Practice
ISC / Class 11 study guide
Concept building + numerical problem solving + examination revision.
Problem-solving method
For every numerical use: Given → Required → Formula → Substitution → Unit → Final answer. Draw a diagram or
free-body diagram whenever it helps.
Note: This is an original study guide, not a reproduction of an official textbook or examination paper.
Class 11 Physics Coursebook • Page 1
,1. Units and Measurements
Detailed notes
A physical quantity has a numerical value and a unit. SI base quantities include metre, kilogram, second, ampere, kelvin,
mole and candela.
Dimensions represent powers of fundamental quantities. Velocity is [LT■¹], acceleration [LT■²], force [MLT■²], energy
[ML²T■²], and pressure [ML■¹T■²].
Significant figures indicate the precision of a measurement. Leading zeros are not significant; zeros between non-zero digits
are significant.
Dimensional analysis checks equations and can help derive relations, but dimensionless numerical constants cannot be
obtained from dimensions alone.
Worked examples
Problem: Convert 72 km h■¹ to m s■¹.
Solution: 72×1000/3600 = 20 m s■¹.
Problem: Find the dimensions of pressure.
Solution: Pressure=force/area=[MLT■²]/[L²]=[ML■¹T■²].
Problem: How many significant figures are in 2.50 m?
Solution: 3 significant figures.
Key formulae
• Percentage error ≈ (absolute error/mean value)×100.
• 1 km=1000 m; 1 h=3600 s.
• [F]=[MLT■²]; [E]=[ML²T■²].
Practice with answers
Problem: 5 m s■¹ in km h■¹?
Solution: 18 km h■¹.
Problem: Dimensions of energy?
Solution: [ML²T■²].
Problem: Significant figures in 0.00450?
Solution: 3.
Problem: SI unit of pressure?
Solution: Pa.
Problem: Is v=u+at dimensionally valid?
Solution: Yes.
15-question self-test
1. What is the main physical quantity studied here?
Identify the quantity, write its SI unit, then choose the governing law.
2. What is the first step in a numerical?
Write the given quantities and the required unknown.
3. Why should units be converted before substitution?
To keep the numerical calculation consistent.
Class 11 Physics Coursebook • Page 2
,4. What does a negative answer usually mean?
Direction relative to the chosen sign convention, not necessarily a negative magnitude.
5. How can a graph help?
Its slope or area may represent a useful physical quantity.
6. What should be checked after solving?
Units, sign, magnitude and limiting behaviour.
7. When should a diagram be drawn?
Whenever geometry, forces, vectors or motion directions could cause confusion.
8. Why are assumptions important?
Many Physics equations hold only under stated conditions such as constant acceleration or negligible air resistance.
9. What is a conservation law useful for?
It can simplify problems by relating initial and final states.
10. What is dimensional analysis good for?
Checking dimensional consistency and deriving possible forms of relations.
11. What is a scalar?
A quantity described by magnitude only.
12. What is a vector?
A quantity with magnitude and direction.
13. Why use SI units?
They provide a consistent system for calculation and communication.
14. What is a common numerical mistake?
Using the wrong formula or mixing units.
15. Best final-answer format?
Value + SI unit + appropriate significant figures.
Class 11 Physics Coursebook • Page 3
, 2. Motion in a Straight Line
Detailed notes
Displacement is the change in position and is a vector; distance is the total path length and is a scalar.
Average velocity is displacement/time. Instantaneous velocity is v=dx/dt. Acceleration is a=dv/dt.
For constant acceleration: v=u+at, s=ut+½at², v²=u²+2as and s=(u+v)t/2.
On a position-time graph, slope gives velocity. On a velocity-time graph, slope gives acceleration and area gives
displacement.
Worked examples
Problem: A car starts from rest with a=2 m s■² for 5 s. Find v.
Solution: v=0+2×5=10 m s■¹.
Problem: For the same car, find displacement.
Solution: s=½(2)(5²)=25 m.
Problem: Velocity changes from 8 to 20 m s■¹ in 4 s. Find acceleration.
Solution: a=(20−8)/4=3 m s■².
Key formulae
• v=u+at.
• s=ut+½at².
• v²=u²+2as.
• s=(u+v)t/2.
Practice with answers
Problem: u=10,a=3,t=4: v?
Solution: 22 m s■¹.
Problem: From rest, a=4,t=6: s?
Solution: 72 m.
Problem: 25 to 5 m s■¹ in 10 s: a?
Solution: −2 m s■².
Problem: u=12,a=0,t=7: s?
Solution: 84 m.
Problem: Area under v-t graph?
Solution: Displacement.
15-question self-test
1. What is the main physical quantity studied here?
Identify the quantity, write its SI unit, then choose the governing law.
2. What is the first step in a numerical?
Write the given quantities and the required unknown.
3. Why should units be converted before substitution?
To keep the numerical calculation consistent.
4. What does a negative answer usually mean?
Class 11 Physics Coursebook • Page 4
Complete Coursebook • Concepts • Derivations • Solved Numericals • Practice
ISC / Class 11 study guide
Concept building + numerical problem solving + examination revision.
Problem-solving method
For every numerical use: Given → Required → Formula → Substitution → Unit → Final answer. Draw a diagram or
free-body diagram whenever it helps.
Note: This is an original study guide, not a reproduction of an official textbook or examination paper.
Class 11 Physics Coursebook • Page 1
,1. Units and Measurements
Detailed notes
A physical quantity has a numerical value and a unit. SI base quantities include metre, kilogram, second, ampere, kelvin,
mole and candela.
Dimensions represent powers of fundamental quantities. Velocity is [LT■¹], acceleration [LT■²], force [MLT■²], energy
[ML²T■²], and pressure [ML■¹T■²].
Significant figures indicate the precision of a measurement. Leading zeros are not significant; zeros between non-zero digits
are significant.
Dimensional analysis checks equations and can help derive relations, but dimensionless numerical constants cannot be
obtained from dimensions alone.
Worked examples
Problem: Convert 72 km h■¹ to m s■¹.
Solution: 72×1000/3600 = 20 m s■¹.
Problem: Find the dimensions of pressure.
Solution: Pressure=force/area=[MLT■²]/[L²]=[ML■¹T■²].
Problem: How many significant figures are in 2.50 m?
Solution: 3 significant figures.
Key formulae
• Percentage error ≈ (absolute error/mean value)×100.
• 1 km=1000 m; 1 h=3600 s.
• [F]=[MLT■²]; [E]=[ML²T■²].
Practice with answers
Problem: 5 m s■¹ in km h■¹?
Solution: 18 km h■¹.
Problem: Dimensions of energy?
Solution: [ML²T■²].
Problem: Significant figures in 0.00450?
Solution: 3.
Problem: SI unit of pressure?
Solution: Pa.
Problem: Is v=u+at dimensionally valid?
Solution: Yes.
15-question self-test
1. What is the main physical quantity studied here?
Identify the quantity, write its SI unit, then choose the governing law.
2. What is the first step in a numerical?
Write the given quantities and the required unknown.
3. Why should units be converted before substitution?
To keep the numerical calculation consistent.
Class 11 Physics Coursebook • Page 2
,4. What does a negative answer usually mean?
Direction relative to the chosen sign convention, not necessarily a negative magnitude.
5. How can a graph help?
Its slope or area may represent a useful physical quantity.
6. What should be checked after solving?
Units, sign, magnitude and limiting behaviour.
7. When should a diagram be drawn?
Whenever geometry, forces, vectors or motion directions could cause confusion.
8. Why are assumptions important?
Many Physics equations hold only under stated conditions such as constant acceleration or negligible air resistance.
9. What is a conservation law useful for?
It can simplify problems by relating initial and final states.
10. What is dimensional analysis good for?
Checking dimensional consistency and deriving possible forms of relations.
11. What is a scalar?
A quantity described by magnitude only.
12. What is a vector?
A quantity with magnitude and direction.
13. Why use SI units?
They provide a consistent system for calculation and communication.
14. What is a common numerical mistake?
Using the wrong formula or mixing units.
15. Best final-answer format?
Value + SI unit + appropriate significant figures.
Class 11 Physics Coursebook • Page 3
, 2. Motion in a Straight Line
Detailed notes
Displacement is the change in position and is a vector; distance is the total path length and is a scalar.
Average velocity is displacement/time. Instantaneous velocity is v=dx/dt. Acceleration is a=dv/dt.
For constant acceleration: v=u+at, s=ut+½at², v²=u²+2as and s=(u+v)t/2.
On a position-time graph, slope gives velocity. On a velocity-time graph, slope gives acceleration and area gives
displacement.
Worked examples
Problem: A car starts from rest with a=2 m s■² for 5 s. Find v.
Solution: v=0+2×5=10 m s■¹.
Problem: For the same car, find displacement.
Solution: s=½(2)(5²)=25 m.
Problem: Velocity changes from 8 to 20 m s■¹ in 4 s. Find acceleration.
Solution: a=(20−8)/4=3 m s■².
Key formulae
• v=u+at.
• s=ut+½at².
• v²=u²+2as.
• s=(u+v)t/2.
Practice with answers
Problem: u=10,a=3,t=4: v?
Solution: 22 m s■¹.
Problem: From rest, a=4,t=6: s?
Solution: 72 m.
Problem: 25 to 5 m s■¹ in 10 s: a?
Solution: −2 m s■².
Problem: u=12,a=0,t=7: s?
Solution: 84 m.
Problem: Area under v-t graph?
Solution: Displacement.
15-question self-test
1. What is the main physical quantity studied here?
Identify the quantity, write its SI unit, then choose the governing law.
2. What is the first step in a numerical?
Write the given quantities and the required unknown.
3. Why should units be converted before substitution?
To keep the numerical calculation consistent.
4. What does a negative answer usually mean?
Class 11 Physics Coursebook • Page 4
