Science

Grade X Physics: Lenses and Mirrors Image Formation Explained with Tables

rajeevvkalra — Fri, 16 May 2025 10:00:41 +0000

Grade X Lens and Mirrors Image Formation Table

Grade X: Lens and Mirrors Image Formation Table

Understanding how images are formed by lenses and mirrors is a foundational concept in Grade X Physics. In this post, we present a detailed and structured explanation of image formation by concave and convex mirrors as well as converging (convex) and diverging (concave) lenses. This guide is designed to help students grasp the key principles with clarity and confidence, with SEO optimization to support better search visibility.

Image Formation by Concave Mirror

Object Position	Image Position	Image Nature
At infinity	At focus (F)	Real, inverted, highly diminished
Beyond C	Between F and C	Real, inverted, diminished
At C	At C	Real, inverted, same size
Between C and F	Beyond C	Real, inverted, magnified
At focus (F)	At infinity	Real, inverted, highly magnified
Between pole and focus	Behind mirror	Virtual, erect, magnified

Image Formation by Convex Mirror

Object Position	Image Position	Image Nature
At any position	Behind mirror (between pole and focus)	Virtual, erect, diminished

Image Formation by Convex Lens

Object Position	Image Position	Image Nature
At infinity	At focus on opposite side	Real, inverted, highly diminished
Beyond 2F	Between F and 2F	Real, inverted, diminished
At 2F	At 2F	Real, inverted, same size
Between F and 2F	Beyond 2F	Real, inverted, magnified
At focus (F)	At infinity	Real, inverted, highly magnified
Between pole and focus	Same side as object	Virtual, erect, magnified

Conclusion

These tables provide a structured overview of how different object positions affect image characteristics when using lenses and mirrors. Mastering these concepts is crucial for success in Grade X Physics and forms the foundation for more advanced optical studies. Bookmark this page and revisit whenever you need a quick revision or deeper understanding of image formation principles.

Arrhenius Equation Numericals Explained: Step-by-Step Solutions with Formulas

rajeevvkalra — Thu, 24 Apr 2025 06:44:07 +0000

Mastering Arrhenius Equation Numericals: Step-by-Step Solutions

What is the Arrhenius Equation?

The Arrhenius equation is a formula used to express the dependence of reaction rate on temperature and activation energy. It is written as:

k = A * e^-Ea/RT

Where:

k = rate constant
A = frequency factor
E_a = activation energy (J/mol)
R = gas constant (8.314 J/mol·K)
T = temperature in Kelvin

Solved Numerical Example 1

Problem: Calculate the rate constant at 350 K for a reaction with an activation energy of 75,000 J/mol and a frequency factor of 1.5 × 10¹³ s^-1.

Solution:

Using the formula: k = A * e^-Ea/RT

Substitute the values:
A = 1.5 × 10¹³, Ea = 75,000 J/mol, R = 8.314 J/mol·K, T = 350 K

Exponent part: Ea/RT = 75000 / (8.314 × 350) ≈ 25.75

e^-25.75 ≈ 6.72 × 10^-12

k = 1.5 × 10¹³ × 6.72 × 10^-12 ≈ 100.8 s^-1

Solved Numerical Example 2

Problem: Determine the activation energy if the rate constant increases from 5.4 × 10³ to 2.7 × 10⁴ when the temperature increases from 300 K to 310 K.

Solution:

Use the logarithmic form: ln(k2/k1) = Ea/R (1/T1 – 1/T2)

ln(2.7 × 10⁴ / 5.4 × 10³) = Ea / 8.314 × (1/300 – 1/310)

ln(5) ≈ 1.609, and (1/300 – 1/310) ≈ 0.0001075

Ea = 1.609 / 0.0001075 × 8.314 ≈ 124,470 J/mol

Posted on April 24, 2025 | By more-marks.com

Pressure Calculation Worksheet with Solutions: Class 8 Science Questions

rajeevvkalra — Wed, 23 Apr 2025 08:05:26 +0000

Pressure Calculations – Questions 11 to 20

Q11. A block weighing 48 N is placed on the ground on its base measuring 0.2 m × 0.4 m. Calculate the pressure it exerts.
Solution: Area = 0.2 × 0.4 = 0.08 m²
Pressure = 48 / 0.08 = 600 Pa

Q12. A suitcase weighing 120 N rests on a trolley with contact area 0.6 m². Calculate the pressure.
Solution: Pressure = 120 / 0.6 = 200 Pa

Q13. A student pushes a wall with a force of 100 N. The area of his hand is 0.05 m². Find the pressure exerted.
Solution: Pressure = 100 / 0.05 = 2000 Pa

Q14. A brick is 40 cm × 10 cm in contact with the floor and weighs 32 N. Find the pressure.
Solution: Area = 0.4 × 0.1 = 0.04 m²
Pressure = 32 / 0.04 = 800 Pa

Q15. A car weighing 10,000 N rests on four tyres. If the total area of contact is 0.5 m², calculate the pressure on the road.
Solution: Pressure = 10,000 / 0.5 = 20,000 Pa

Q16. A book weighing 10 N is placed on its side of 0.2 m × 0.03 m. Calculate the pressure on the table.
Solution: Area = 0.2 × 0.03 = 0.006 m²
Pressure = 10 / 0.006 = 1666.67 Pa

Q17. A hammer strikes a surface with a force of 300 N over a very small area of 0.002 m². What is the pressure?
Solution: Pressure = 300 / 0.002 = 150,000 Pa

Q18. A rectangular tile exerts a pressure of 1000 Pa on the floor. If its weight is 50 N, find the area in contact.
Solution: Area = 50 / 1000 = 0.05 m²

Q19. A force of 60 N acts on a nail head with an area of 0.0001 m². Calculate the pressure.
Solution: Pressure = 60 / 0.0001 = 600,000 Pa

Q20. A cement bag weighs 500 N and has a base area of 0.25 m². What pressure does it exert on the ground?
Solution: Pressure = 500 / 0.25 = 2000 Pa

Mastering Numerical Problems on Pressure: Formulas, Solutions & Tips

Understanding how to calculate pressure is a fundamental concept in physics, especially in fluid mechanics and mechanics. Whether you’re a student preparing for exams or a teacher seeking clear examples, this guide provides a comprehensive set of numerical problems on pressure with step-by-step solutions. Optimized for clarity and comprehension, these questions help reinforce your grasp on the core formula:

Pressure (P) = Force (F) / Area (A)

Let’s explore 10 well-structured numerical problems involving pressure, force, and area, each explained in detail with answers highlighted for quick learning.

10 Numerical Questions on Pressure with Detailed Solutions

Q1. Calculating Pressure from Force and Area

Question: A force of 300 N is applied on a surface of area 6 m². Calculate the pressure exerted.

Solution: Pressure = 300 / 6 = 50 Pa

Q2. Pressure Exerted by a Man Standing on One Foot

Question: A man of weight 700 N stands on one foot. If the area of the foot in contact with the ground is 0.02 m², find the pressure exerted on the ground.

Solution: Pressure = 700 / 0.02 = 35,000 Pa

Q3. Pressure from a Box on a Platform

Question: A box weighing 500 N is placed on a wooden platform of area 2.5 m². Calculate the pressure it exerts on the platform.

Solution: Pressure = 500 / 2.5 = 200 Pa

Q4. Finding Force from Pressure and Area

Question: A pressure of 150 Pa is acting on a surface area of 4 m². Find the force exerted.

Solution: Force = 150 × 4 = 600 N

Q5. Calculating Pressure on a Small Area

Question: A force of 250 N is exerted on a small area of 0.5 m². What is the pressure?

Solution: Pressure = 250 / 0.5 = 500 Pa

Q6. Pressure from a Plank on a Surface

Question: A rectangular plank has a weight of 1000 N. If it rests on a surface area of 8 m², what is the pressure?

Solution: Pressure = 1000 / 8 = 125 Pa

Q7. Pressure Due to an Elephant’s Leg

Question: An elephant exerts a force of 3000 N with each leg. If the area of contact of one leg with the ground is 0.1 m², find the pressure on the ground due to one leg.

Solution: Pressure = 3000 / 0.1 = 30,000 Pa

Q8. Drawing Pin Pressure

Question: A drawing pin exerts a force of 5 N over an area of 0.001 m². Calculate the pressure applied by the pin.

Solution: Pressure = 5 / 0.001 = 5000 Pa

Q9. Child Standing on Both Feet

Question: A child weighing 350 N stands on both feet. If the total contact area of the feet is 0.025 m², find the pressure.

Solution: Pressure = 350 / 0.025 = 14,000 Pa

Q10. Finding Area from Force and Pressure

Question: A force of 180 N acts perpendicularly on a surface. The pressure exerted is 30 Pa. What is the area of the surface?

Solution: Area = 180 / 30 = 6 m²

Conclusion

Mastering pressure calculations is essential for understanding how forces distribute across surfaces, whether in engineering, physics, or daily life. These numerical questions provide practical insights into how small or large pressures can arise based on the area involved. Use this guide as a practice tool or a teaching resource to solidify your understanding of pressure concepts.

Force and Pressure Class 8: Most Important Questions and Answers Explained

rajeevvkalra — Mon, 07 Apr 2025 08:15:17 +0000

Fill in the blanks

rajeevvkalra — Mon, 24 Mar 2025 11:56:25 +0000

MCQs: Nutrition and Health

Set A: Nutrition and Health

Question 1: Polio is caused by which of the following?

a) Bacteria b) Virus c) Fungus d) Parasite

Question 2: Which nutrient is primarily responsible for providing energy for daily activities?

a) Proteins b) Vitamins c) Carbohydrates d) Minerals

Question 3: Which of the following foods is a good source of proteins?

a) Apples b) Eggs c) Bread d) Butter

Question 4: Which nutrient helps in the growth and repair of body tissues?

a) Carbohydrates b) Proteins c) Fats d) Vitamins

Question 5: Vitamins are essential for:

a) Providing energy b) Growth and repair of tissues c) Normal body functions d) Adding bulk to the undigested food

Question 6: Which of the following is a good source of vitamins?

a) Rice b) Bread c) Green leafy vegetables d) Butter

Question 7: Minerals are needed for:

a) Growth and repair of tissues b) Providing energy c) Proper functioning and maintenance of body structures d) Normal body functions

Set B: Water, Roughage, and Balanced Diet

Question 8: Water is essential for:

a) Providing energy b) Normal body functions c) Movement of food through the stomach and intestines d) Growth and repair of tissues

Question 9: Roughage helps in:

a) Providing energy b) Normal body functions c) Movement of food through the stomach and intestines d) Growth and repair of tissues

Question 10: A balanced diet should include:

a) Only carbohydrates and proteins b) Only fats and vitamins c) A variety of foods containing all necessary nutrients d) Only minerals and water

Question 11: How many servings of rice and cereals should be consumed daily according to a balanced diet?

a) 1-2 servings b) 2-3 servings c) 3-4 servings d) 5-7 servings

Question 12: Protein-rich foods include:

a) Bread and butter b) Rice and cereals c) Dairy products and pulses d) Fruits and vegetables

Question 13: In a balanced diet, oil, fat, and sugar should be consumed in:

a) Large amounts b) Moderate amounts c) Small amounts d) Very small amounts

Set C: Exercise, Sleep, and Diseases

Question 14: Regular exercise and proper sleep help in:

a) Providing energy b) Maintaining physical fitness and overall well-being c) Growth and repair of tissues d) Normal body functions

Question 15: Essential nutrients must be obtained from:

a) External food sources b) Internal body production c) Water alone d) Air

Question 16: Diseases that can spread from one person to another are called:

a) Non-communicable diseases b) Genetic diseases c) Communicable diseases d) Nutritional diseases

Question 17: Non-communicable diseases:

a) Can spread from one person to another b) Cannot spread from one person to another c) Are caused by bacteria d) Are caused by viruses

Question 18: Which of the following is an example of a communicable disease?

a) Diabetes b) Heart disease c) Common cold d) Cancer

Set D: Modes of Transmission and Prevention of Communicable Diseases

Question 19: Air-borne diseases spread through:

a) Direct contact b) Indirect contact c) Contaminated food d) Air

Question 20: Which of the following diseases is caused by contaminated food or water?

a) Malaria b) Chickenpox c) Diarrhea d) Measles

Question 21: Diseases spread by direct or indirect contact include:

a) Malaria b) Chickenpox c) Diarrhea d) Typhoid

Question 22: Insects like mosquitoes spread diseases such as:

a) Diarrhea b) Typhoid c) Malaria d) Chickenpox

Question 23: Preventive measures for communicable diseases include:

a) Maintaining personal hygiene b) Avoiding vaccinations c) Consuming junk food d) Ignoring infected individuals

Question 24: Vaccinations help prevent diseases by:

a) Eliminating germs b) Producing immunity c) Removing toxins d) Healing wounds

Question 25: Which of the following terms describes the body’s natural ability to fight against germs?

a) Immunity b) Deficiency c) Transmission d) Contamination

Question 26: Non-communicable diseases can result from:

a) Direct contact with infected individuals b) Deficiencies in vitamins and minerals c) Contaminated food and water d) Insect bites

Set E: Deficiency Diseases, Inherited Diseases, and Vaccination

Question 27: A deficiency of Vitamin D can lead to:

a) Night blindness b) Scurvy c) Rickets d) Beriberi

Question 28: Which vitamin deficiency causes night blindness?

a) Vitamin A b) Vitamin B1 c) Vitamin C d) Vitamin D

Question 29: Which mineral deficiency leads to anemia?

a) Calcium b) Iodine c) Iron d) Potassium

Question 30: Edward Jenner is associated with the discovery of the vaccine for:

a) Polio b) Smallpox c) Tuberculosis d) Measles

Question 31: Inherited non-communicable diseases are:

a) Related to lifestyle b) Present from birth c) Caused by bacteria d) Spread through air

Question 32: Preventive measures for deficiency diseases include consuming:

a) Junk food b) Processed food c) A balanced diet d) Only water

Question 33: Scurvy is caused by a deficiency of:

a) Vitamin A b) Vitamin B1 c) Vitamin C d) Vitamin D

Science worksheet grade Viii

rajeevvkalra — Mon, 17 Mar 2025 12:28:37 +0000

Physics Questions and Solutions

Question: The pressure which is exerted by air around us is known as:

a) Force

b) Atmospheric pressure

c) Muscular force

d) Friction

Answer: b) Atmospheric pressure
Question: The force exerted by the earth to pull the object towards itself is called:

a) Electrostatic force

b) Gravitational force

c) Muscular force

d) Contact Force

Answer: b) Gravitational force
Question: One Kilogram weight is equal to:

a) 98 N

b) 9.8 N

c) 0.98 N

d) 0.098 N

Answer: b) 9.8 N
Question: When two forces act in opposite directions, then the net force acting is the:

a) Sum of two forces

b) Difference between two forces

c) Both of these

d) None of these

Answer: b) Difference between two forces
Question: Which of the following forces is a contact force?

a) Force of gravity

b) Magnetic force

c) Force of friction

d) Electrostatic force

Answer: c) Force of friction
Question: If we release a magnet held in our hand, it falls to the ground. The force responsible for this is:

a) Muscular force

b) Magnetic force

c) Electrostatic force

d) Gravitational force

Answer: d) Gravitational force
Question: A brick is kept in three different ways with the help of V, L, O shapes on a table. The pressure exerted by the brick on the table will be:

a) Maximum in position V

b) Maximum in position O

c) Maximum in position L

d) Equal in all cases

Answer: d) Equal

Science worksheet set 16

rajeevvkalra — Fri, 28 Feb 2025 19:24:36 +0000

Science Worksheet (Set 16) – Questions and Answers

Science Worksheet (Set 16)

Topic: Circulatory System & Muscular System

Grade: VII

Q1. Answer the following questions:

a. Imagine the septum between the left and right sides of the heart has a hole. Predict how this condition might affect the circulatory system.

– The septum separates oxygenated and deoxygenated blood in the heart.
– A hole in the septum will cause mixing of oxygen-rich and oxygen-poor blood, leading to reduced oxygen supply to body tissues.
– This can result in fatigue, shortness of breath, and improper organ function.

b. Identify the type of muscle shown in the given picture. Write any two characteristics of the given muscle.

– The given image shows cardiac muscle.
– Characteristics:
1. Involuntary and rhythmic contractions: Cardiac muscles contract on their own without conscious control.
2. Striated appearance: They have a striped (striated) texture under a microscope.

Science worksheet set 15

rajeevvkalra — Fri, 28 Feb 2025 19:22:26 +0000

Science Worksheet (Set 15)

Topic: Transport in Animals and Plants

Grade: VII

Q1. Answer briefly:

a. How do plants excrete waste products?

– Plants excrete waste through stomata (gas exchange), lenticels (in woody plants), and through the process of transpiration.
– Some plants store waste in leaves, bark, or fruits, which later shed.

b. Each kidney contains about a million tiny __________ where the process of urine formation takes place.

Nephrons

c. Aquatic animals excrete solid waste in gaseous form called __________, while land animals excrete a white semi-colored compound called __________ because of less intake of water.

– Ammonia (aquatic animals)
– Uric acid (land animals)

d. Systole: __________ (Fill in the blank)

Systole refers to the phase of the heartbeat when the heart contracts to pump blood.

e. Veins have __________ to prevent the backflow of blood.

Valves

Q2. Answer the following questions:

a. What is the function of platelets in the blood, and why is their normal count essential for the body?

– Function: Platelets help in blood clotting, preventing excessive bleeding during injuries.
– Importance: A low platelet count can lead to excessive bleeding, while a high platelet count may cause blood clots, leading to complications.

b. A farmer is growing vegetables in a field where the soil has become dry due to a lack of rainfall. The farmer waters the plants, and after some time, notices that the leaves appear fresh and upright again.

i. What process allows water to move into the plant’s roots from the soil?

Osmosis (movement of water from a region of higher concentration in the soil to lower concentration in the root cells).

ii. If a concentrated salt solution is poured near the plant roots instead of water, what might happen to the plant cells? Explain your answer using the concept of osmosis.

– The high salt concentration outside the roots will cause water to move out of the plant cells (due to osmosis).
– This will lead to plasmolysis, where plant cells shrink, making the plant wilt and eventually die.

iii. Differentiate between the movement of water (osmosis) and the movement of oxygen gas into the cells during respiration (diffusion).

Osmosis	Diffusion
Movement of water molecules through a semi-permeable membrane.	Movement of gases or solutes from high to low concentration.
Requires a semi-permeable membrane.	Does not require a membrane.
Example: Water absorption by plant roots.	Example: Oxygen entering cells for respiration.

c. Why are arteries more prone to damage from high blood pressure compared to veins? Why are veins less affected?

– Arteries carry blood under high pressure, which puts more strain on their walls, making them more susceptible to damage.
– Veins carry blood under low pressure and have valves that help prevent backflow, reducing the risk of damage.

Electricity and magnetism worksheet set 14

rajeevvkalra — Fri, 28 Feb 2025 19:19:42 +0000

Class 7 Science Worksheet on Electricity and Magnetism | Set 14

This Class 7 Science Worksheet on Electricity and Magnetism covers essential topics such as circuits, solenoids, fuses, resistance, and electrolysis. Designed to align with the CBSE and NCERT curriculum, this worksheet helps students understand the core concepts of electricity and magnetism while preparing them for exams and real-world applications.

Q1: Answer the Following Questions

a. Why are filament-type electric bulbs not power-efficient? Name two energy-efficient alternatives.

Filament-type electric bulbs waste most of their energy as heat rather than light, making them inefficient. Two energy-efficient alternatives are:

LED (Light Emitting Diode) bulbs
CFL (Compact Fluorescent Lamp) bulbs

b. What is a Fuse and Why is it Important?

i. What is the purpose of a fuse in a circuit?

A fuse is a safety device that protects electrical circuits by melting and breaking the circuit when there is an overload or short circuit, preventing damage to appliances and potential fires.

ii. What happens if a fuse is missing?

Without a fuse, excessive current can flow through the circuit, leading to overheating, fires, or damage to connected devices.

c. Why is an electrolyte necessary for electrolysis? Can pure water undergo electrolysis?

An electrolyte is necessary because it provides free ions that conduct electricity during electrolysis. Pure water cannot undergo electrolysis effectively because it lacks sufficient free ions. Adding an electrolyte like salt or acid is required to enable the process.

d. Why does resistance increase with temperature in a conductor?

As temperature increases, the atoms in a conductor vibrate more vigorously, obstructing the flow of electrons. This increased obstruction results in higher resistance.

Q2: Case Study – Lifting Heavy Objects with Solenoids

In factories, solenoids (electromagnets) powered by batteries are used to lift heavy metal objects efficiently.

a. Why use a solenoid instead of a permanent magnet?

Solenoids are preferred because they can be turned on and off, providing better control over lifting and releasing objects. Permanent magnets, on the other hand, cannot be deactivated easily.

b. What happens if the solenoid is disconnected from the battery?

When disconnected, the solenoid loses its magnetic field, causing the metal object to fall.

c. How can the solenoid lift heavier objects?

To lift heavier objects:

Increase the number of coils in the solenoid.
Use a stronger battery to increase the current and strengthen the magnetic field.

Real-Life Applications of Electricity and Magnetism

Electricity powers everyday devices like lights, fans, computers, and industrial machinery.
Magnetism is used in motors, generators, and magnetic cranes.
Electromagnets are widely used in recycling plants to separate metal objects from waste.

FAQs

1. What are the two industries where electromagnets are widely used?

Electromagnets are widely used in the automotive industry (e.g., in car lifts) and the recycling industry (e.g., for separating metals).

2. Why are CFLs preferred over filament bulbs?

CFLs are preferred because they are more energy-efficient, produce less heat, and have a longer lifespan compared to filament bulbs.

3. What is the SI unit of resistance?

The SI unit of resistance is the Ohm (Ω).

1. What is the difference between an electromagnet and a permanent magnet?

An electromagnet is a temporary magnet that works only when electric current flows through it. A permanent magnet, like a bar magnet, retains its magnetism without an external power source.

2. How does a circuit breaker work?

A circuit breaker automatically interrupts the flow of current when it detects an overload or short circuit, preventing damage to the circuit and appliances.

3. What is the role of resistance in a circuit?

Resistance controls the flow of current in a circuit. It is measured in ohms (Ω) and ensures that devices receive the correct amount of current.

Conclusion

This Class 7 Science Worksheet on Electricity and Magnetism provides a comprehensive set of questions and answers to help students master key concepts. By practicing these questions, students can strengthen their understanding of circuits, solenoids, fuses, and more, preparing them for both exams and real-world applications. For more resources, check out our Class 7 Science Worksheet on Light and Sound.

Science

Grade X Physics: Lenses and Mirrors Image Formation Explained with Tables

Grade X: Lens and Mirrors Image Formation Table

Image Formation by Concave Mirror

Image Formation by Convex Mirror

Image Formation by Convex Lens

Conclusion

Arrhenius Equation Numericals Explained: Step-by-Step Solutions with Formulas

Mastering Arrhenius Equation Numericals: Step-by-Step Solutions

Solved Numerical Example 1

Solved Numerical Example 2

Pressure Calculation Worksheet with Solutions: Class 8 Science Questions

Pressure Calculations – Questions 11 to 20

Top 10 Solved Numerical Questions on Pressure with Step-by-Step Solutions

Mastering Numerical Problems on Pressure: Formulas, Solutions & Tips

10 Numerical Questions on Pressure with Detailed Solutions

Q1. Calculating Pressure from Force and Area

Q2. Pressure Exerted by a Man Standing on One Foot

Q3. Pressure from a Box on a Platform

Q4. Finding Force from Pressure and Area

Q5. Calculating Pressure on a Small Area

Q6. Pressure from a Plank on a Surface

Q7. Pressure Due to an Elephant’s Leg

Q8. Drawing Pin Pressure

Q9. Child Standing on Both Feet

Q10. Finding Area from Force and Pressure

Conclusion

Force and Pressure Class 8: Most Important Questions and Answers Explained

Top Questions and Answers on Force and Pressure – Class 8 Science Guide

What is Force in Science?

Types of Forces and Their Effects

Friction and Muscular Force

Gravitational and Magnetic Forces

Electrostatic and Atmospheric Pressure

Understanding Pressure

Pressure in Liquids and Gases

Conclusion: Why You Should Master Force and Pressure

Fill in the blanks

Set A: Nutrition and Health

Set B: Water, Roughage, and Balanced Diet

Set C: Exercise, Sleep, and Diseases

Set D: Modes of Transmission and Prevention of Communicable Diseases

Set E: Deficiency Diseases, Inherited Diseases, and Vaccination

Science worksheet grade Viii

Physics Questions and Solutions

Science worksheet set 16

Science Worksheet (Set 16)

Topic: Circulatory System & Muscular System

Grade: VII

Q1. Answer the following questions:

Science worksheet set 15

Science Worksheet (Set 15)

Topic: Transport in Animals and Plants

Grade: VII

Q1. Answer briefly:

Q2. Answer the following questions:

Electricity and magnetism worksheet set 14

Class 7 Science Worksheet on Electricity and Magnetism | Set 14

Q1: Answer the Following Questions

a. Why are filament-type electric bulbs not power-efficient? Name two energy-efficient alternatives.

b. What is a Fuse and Why is it Important?

i. What is the purpose of a fuse in a circuit?

ii. What happens if a fuse is missing?

c. Why is an electrolyte necessary for electrolysis? Can pure water undergo electrolysis?

d. Why does resistance increase with temperature in a conductor?

Q2: Case Study – Lifting Heavy Objects with Solenoids

a. Why use a solenoid instead of a permanent magnet?

b. What happens if the solenoid is disconnected from the battery?

c. How can the solenoid lift heavier objects?

Real-Life Applications of Electricity and Magnetism

FAQs

1. What are the two industries where electromagnets are widely used?

2. Why are CFLs preferred over filament bulbs?

3. What is the SI unit of resistance?

1. What is the difference between an electromagnet and a permanent magnet?

2. How does a circuit breaker work?

3. What is the role of resistance in a circuit?

Conclusion