# List of Physics and Chemistry Formulas For Exams 2023

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## Physics Formulas

Physics is a subject that emphasizes understanding rather than rote memorization. It is particularly challenging as it demands a high level of attentiveness. At Dream Big Institution, the team provides a collection of formulas that not only enhance comprehension but also expand thinking capabilities. These formulas serve as a valuable resource, enabling students to delve deeper into the subject and develop a broader perspective.

### Important Physics Formulas

Given below is the most important Physics formulae list:

• Planck constant h = 6.63 × 10−34 J.s = 4.136 × 10-15 eV.s
• Gravitation constant G = 6.67×10−11 m3 kg−1 s−2
• Boltzmann constant k = 1.38 × 10−23 J/K
• Molar gas constant R = 8.314 J/(mol K)
• Avogadro’s number NA = 6.023 × 1023 mol−1
• Charge of electron e = 1.602 × 10−19 C
• Permittivity of vacuum 0 = 8.85 × 10−12 F/m
• Coulomb constant 1/4πε0 = 8.9875517923(14) × 109 N m2/C2
• Faraday constant F = 96485 C/mol
• Mass of electron me = 9.1 × 10−31 kg
• Mass of proton mp = 1.6726 × 10−27 kg
• Mass of neutron mn = 1.6749 × 10−27 kg
• Stefan-Boltzmann constant σ = 5.67 × 10−8 W/(m2 K4)
• Rydberg constant R∞ = 1.097 × 107 m−1
• Bohr magneton µB = 9.27 × 10−24 J/T
• Bohr radius a0 = 0.529 × 10−10 m
• Standard atmosphere atm = 1.01325 × 105 Pa
• Wien displacement constant b = 2.9 × 10−3 m K .
• Wave = ∆x ∆t wave = average velocity ∆x = displacement ∆t = elapsed time.
• Vavg = (vi + vf*)2

Vavg = The average velocity

vi = initial velocity

vf = final velocity

• a = ∆v ∆t,

a = acceleration

∆v = change in velocity

∆t = elapsed time.

• ∆x = vi∆t + 1/2 a(∆t)2

∆x = the displacement

vi = the initial velocity

∆t = the elapsed time

a = the acceleration

• ∆x = vf∆t − 1/2 a(∆t)2

∆x = displacement

vf = is the final velocity

∆t = elapsed time

a = acceleration

• F = ma

F = force

m = mass

a = acceleration

• W = mg

W = weight

m = mass

g = acceleration which is due to gravity.

• f = µN

f = friction force

µ = coefficient of friction

N = normal force

• p = mv
• W = F d cos θ or W = F!d

W = work t

F = force

d = distance

θ = angle between F and the direction of motion

• KE  = 1/2 mv2 K

KE = kinetic energy

m = mass

v = velocity

• PE = mgh

PE = potential energy

m = mass

g = acceleration due to gravity

h = height

• W = ∆(KE)

W = work done

KE = kinetic energy.

• P = W ∆t

P = power

W = work

∆t = elapsed time

### Solved Examples

Q.1. Calculate the dc voltage drop if the circuit length is 500 cms and in it 10 A of current flows in 20 s ?

Solution:

The DC voltage drop is given as : V=L×I/T

where, I = current through the circuit in Amperes.

L = Length of the circuit in metres

T = time for which the current has flowed through the circuit in seconds

V = Voltage in Volts.

So,

V=500×10/20

V = 0.25 Volts.

Q.2. The spring constant of a stretched string is 50Nm−1 and displacement is 20 cm. Compute potential energy stored in the stretched string.

Solution:

Given parameters are,

k=50Nm−1

x = 20 cm = 0.2 m

Potential energy will be:

P.E=1/2k×x2

=½ X 50×(0.2)2

= 1 J

Q.3. A body moves along the x- axis according to the relation x=1–2t+3t2x=1–2t+3t2x = 1 – 2 t + 3t^{2}, where x is in metres and t is in seconds. Find the Acceleration of the body when t = 3s

Solution:

We have,

x=1–2t+3t2x=1–2t+3t2x = 1 – 2 t + 3t^{2}then;

Velocity v= dx/dt= −2+6t

v= dx/dt= −2+6t

Acceleration:  v=dv/dt =6(m/s2)

Q.4. Calculate the weight of an object on the moon which weighs 50kg on earth.

Solution:

Here weight = mass x gravitational acceleration

= m x g

= 50 kg x 1.6 m/s2

= 80 Kg m/s2

Q.5. Find the displacement covered by an object which accelerates from rest to 60 m/s in 3s.

Solution:

Initial velocity = 0 and final velocity = 60 m/s

Time taken = 3s

Therefore, acceleration = 60/3 = 20m/s2.

Displacement (S) = ut + ½ at2

= 90 m

Q.6. A person goes from Point A to Point B in 10s and returns back in 8s. If the distance between A and B is 36m, find the average speed of the person.

Solution:

Here total distance covered = 72m

Total time taken = 18s

Therefore, average speed  = Total distance covered/Total time taken

=72/18

Total distance covered total time taken=7218

= 4 m/s.

Q.7. If an object is moving with a velocity of 5 m/s and has a kinetic energy of 100J, Find its mass.

Solution:

We know that KE = ½ mv2

100 = ½ x m x 5 x 5

100 = 25 m/2

m = 100×2/25 = 200/25

= 8 kg

Q.8. A long thin rod of length 50 cm has a total charge of 5 mC uniformly distributed over it. Find the linear charge density.

Solution:

q = 5 mC = 5 × 10–3 C, l= 50 cm = 0.5 m. λ=?

λ=ql

=(5×10^−3)/0.5

=(5×10^−3)/0.5

=10^-2Cm^−1

Q.9. A car is travelling with a velocity of 10 m/s and it has a mass of 250 Kg. Compute its Kinetic energy?

Solution:

As given here,

Mass of the body, m = 250 Kg,

Velocity of it, v = 10 m/s,

So Kinetic energy will be as:

E = 1/2mv^2

E = 1/2×250×10^2

= 125 ×100

E = 12500 joules

Q.10. The heat needed for a phase transfer of a 2 kg substance is 400k.cal. Determine its latent heat.

Solution:

Given parameters are,

Q = 400 k.cal

M = 2 kg

The formula for latent heat is given by,

L = Q / M

L = 400 / 2

L = 200 k.cal/kg

## How to use Physics formulas effectively

When you reach class 11, the practical application of physics becomes more apparent, especially in mechanics. This branch of physics offers a multitude of fascinating concepts to explore. Here, you will learn how to apply physics formulas to solve numerical problems and how to integrate multiple concepts seamlessly. Whether you are tackling objective or subjective questions, two crucial elements come into play: a clear understanding of the underlying concepts and the skillful utilization of physics formulas.

To effectively utilize physics formulas, it is advisable to begin by thoroughly studying the chapter. Alongside this, you can download the Physics Wallah physics formula sheet specific to that chapter. Familiarize yourself with all the formulas and then proceed to solve numerical problems. This approach enables you to develop a solid grasp of the subject matter and comprehend the practical application of the physics formulas.

Furthermore, the physics formula sheet proves invaluable during last-minute revisions, particularly in the week leading up to your exams. By reviewing the entire sheet of physics formulas before the final exam, you can expedite the syllabus completion process and enhance the efficiency of your revision. Last-minute revisions have the potential to significantly improve your grades, making it highly recommended to create personalized notes with the aid of the physics formula sheet. Writing down the formulas and concepts reinforces your understanding and aids in retaining the information effectively.

## Chemistry Formulas

Chemistry, a branch of science that explores the physical and chemical properties of substances, plays a crucial role in the formation of new materials. It encompasses the study of all the elements present in nature, each possessing a distinct name derived from chemical investigations. These chemical proportions and compositions are represented by formulas, commonly known as chemical formulas.

Chemical formulas serve as a means for scientists to express the precise arrangement of atoms within a molecule or a chemical compound. They utilize the symbols of chemical elements along with numerical subscripts to indicate the number of atoms involved. To facilitate comprehension, a chemistry formula table is often employed to aid in understanding and applying these formulas effectively.

### Types of Chemistry Formulae or Chemical Formulae

There are three types of chemical formulae:

• Molecular Formula
• Empirical Formula
• Structural Formula

Molecular Formula: Molecular formula also known as true formula provides us with the exact number of atoms of every element present in a molecule. The numerical subscripts after the chemical symbols denote the total number of atoms present. The molecular formula also tells us about the type of atom present in a molecule of a compound. Below is an example of a molecular formula.

Molecular Formula of glucose: C₆H₁₂O₆

It represents the actual number of atoms of each constituent (Carbon, Hydrogen and Oxygen) in one molecule of glucose.

Empirical Formula: The word empirical represents something that can be assessed through observation. As such the empirical formula which is more than often emanated from experimental data is defined as the simplest ratio of all the atoms present in the elements that make up a compound. An example of empirical formula extracted by simplifying the molecular formula of glucose:

Empirical formula of glucose: CH₂O

It represents the whole ratio number of the atoms present that is, C, H and O

Structural Formula: While it is good to have chemical formulas in an easy and compact manner, it is also important to know the arrangements of atoms in them. The structural formula tells us about atomic bonding and their arrangement in spaces. It helps us to identify which atoms are bonded with one another and which are not. Given below is an example of the structural formula of glucose which represents the atomic bonding and arrangement.

### How to Write Chemical Formulas?

A chemical formula can be written by the name of the elements that constitute a compound along with some basic rules and in a reverse manner.

1. Chemical formulas of binary compounds which are made of two different elements can be written with the help of valency.
2. The capacity of the combination of the elements to form a compound or compound is known as valency.
3. Firstly the valencies of the two elements should be determined and then the sums of the valencies of the two different elements should be made equal by specifying the common lowest multiple of the two valencies.
4. Cation is an atom with positive charge and anion is an atom with a negative charge. In case if a metal and non-metal are present, the metal should be placed first in the formula. For example NaCl, in which Na has a positive charge and Cl has a negative charge.

Let’s take an example of balanced

Aluminium oxide:

O = 2 (belongs to group VI)

Al = 3 (belongs to group III)

Lowest common multiple of the valencies is 6,

O : 2 x 3 = 6

Al : 3x 2 = 6

The chemical formula of Aluminium oxide is Al₂O₃

### Steps to Write a Chemical Reaction

It is important to note that balancing of chemical equations plays a major role in this process.  Basically, four rules are followed while writing a chemical equation. Let’s have a look below,

1. On the left side of the equation, the right number of reactants is written.
2. On the right side of the equation, the right formulas constituting the products are written.
3. Both the reactants and the products are partitioned by an arrow which points towards the products. This arrow indicates “to produce”.
4. With the help of plus signs various products and reactants are separated. The plus sign indicates ” reacts with” on the reactants side and it means “and”  on the products side.

Let’s take an example of a balanced chemical reaction where hydrogen and chlorine will react to make HCl.

The first step involves writing the equation in terms of the formulas of both the elements, both of which are diatomic in nature.

H2 + Cl2 → HCl

There are two hydrogen atoms and chlorine atoms on the reactants side and one atom each on the product which can be now fixed and balanced by the inclusion of the coefficient 2 on the side of the product.

H2 + Cl2 → 2HCl

Now both the sides are balanced having two hydrogen and chlorine atoms each.

Some examples of chemical reactions are listed below:

Photosynthesis: 6CO2 + 6H2O  → C6H12O6 + 6O2 + 6H2O

Calcium carbonate formation: CaCl2 + Na2CO3 → CaCO3 + 2NaCl

Iron rusting: 4Fe + 3O2 + 6H2O → 4Fe(OH)3.

Combustion of hydrogen: 2H2(g) + O2(g) → 2H2O(l )

Table of Chemical Formulas (Molecular)

### List of Chemical Compound Formulas

Compounds are basically substances that constitute two elements or more in a definite percentage. With the help of chemical formulas, the atoms of the elements in a compound can be known. The list below shows some chemical compounds along with their chemical formulas.

## Physics Formulas and Chemistry Formulas (FAQs)

### Q: Why are formulas important in physics and chemistry?

A: Formulas are essential in physics and chemistry as they provide concise representations of relationships and principles within these disciplines. They allow scientists and students to calculate and predict various physical and chemical phenomena, solving problems and understanding the underlying concepts.

### Q: How can I effectively learn and remember physics and chemistry formulas?

A: Here are a few strategies:
Understand the concepts behind the formulas instead of memorizing them blindly.
Practice applying the formulas to solve numerical problems and real-world scenarios.
Create summary sheets or flashcards with the formulas and review them regularly.
Use mnemonic devices or visualization techniques to associate formulas with memorable cues.
Seek out resources like textbooks, online tutorials, or educational platforms that provide explanations and examples.

### Q: Are there any common misconceptions about using formulas in physics and chemistry?

A: One common misconception is that formulas are merely equations to be memorized without understanding their significance. However, it’s crucial to grasp the underlying principles and concepts associated with each formula to use them effectively. Another misconception is that formulas are rigid and unchanging, whereas they are often derived or modified based on new scientific discoveries and advancements.

### Q: How can I apply physics and chemistry formulas to real-life situations?

A: Physics and chemistry formulas find practical applications in numerous real-life scenarios. For example, physics formulas are used in engineering for designing structures, calculating forces, and analyzing motion. In chemistry, formulas aid in determining chemical reactions, quantifying amounts of substances, and understanding the behavior of compounds in various conditions. By understanding and applying these formulas, you can better comprehend the world around you.