CBSE Class 7 Science Light Worksheets with Answers - Chapter 15 - PDF

The NCERT curriculum is primarily used by the Central Board of Secondary Examination (CBSE). Students taking the class 7 Science exam in 2024-25 should be familiar with the most recent and updated syllabus. Students must understand the CBSE Class 7 Science syllabus in order to flourish in the subject. This level of knowledge is critical because it allows you to grasp the fundamental concepts of the Science subject and ensures a high result on the Class 7 yearly exam. The Class 7 Science syllabus for 2024-25 is divided into 18 chapters that cover a wide range of theory-based and application-based science activities.

Short Notes on CBSE Class 7 Chapter - 15 Light

What Exactly is Light?

Light is a type of energy that our eyes can perceive as a sort of radiation. Because of light, we can see our environment. From one place to another, light travels in a straight line. For example, if we gaze at a candle's flame using a straight pipe, we can clearly see the candle. We can't see the candle or the light coming through the pipe if we bend it, though, because it's blocked.

Light Reflection:

When light strikes an object, it is either absorbed or reflected back to the source. The phenomenon of an object reflecting the light that falls on it is known as light reflection. As a result, the course of light is altered through reflection.

Any shiny surface that can reflect light is referred to as a mirror. A flat-surfaced mirror is known as a plane mirror. A Curved Mirror is a curved mirror that bulges in one direction or out the other.

What Exactly is an Image?

Light reflects off of a mirror, it creates a picture of the item in front of it. The impression of an object formed by the light on the mirror is known as the image of an object. The distance between the image and the mirror, as well as the distance between the item and the mirror, is always the same. When the distance between the item and the mirror is increased or decreased, the distance between the image and the mirror is similarly increased or decreased.

The size of the picture generated on the mirror, on the other hand, can change depending on the distance between the object and the mirror. The size of the picture decreases as the distance between the item and the mirror rises, and vice versa. If the image is produced with the same side up as the item, it is said to be erect. If the image is generated upside-down in comparison to the object, it is called Inverted.

The Laws of Light Reflection: 

• Incident Ray - An incident ray is a light ray that strikes a reflecting surface.

• Reflected Ray - A Reflected Ray is a light ray that is reflected back from a reflecting surface.

• At the point of incidence of Incident Ray, the normal is a line that is perpendicular to the reflected plane.

Reflection Styles:

The reflection of light varies depending on the surface of the reflecting object.

• Diffused Reflection (or Irregular Reflection): In this sort of reflection, light rays falling on the surface are reflected back in a random pattern. This is most likely to happen with an uneven or rough-surfaced object.

• Regular Reflection: The light rays that fall on the surface of the reflecting item reflect back in a specific direction in this sort of reflection. The rays that are reflected are always parallel to one other. This is more common when the surface is smooth and polished.

Mirrors That are Spherical:

Spherical mirrors have a sphere-like form, as the name implies. It has the appearance of being a sphere. Spherical mirrors are divided into two categories:

• A spherical mirror having an inwardly curved reflecting surface is known as a concave mirror.

• A convex mirror is a spherical mirror with a curved reflecting surface that faces outwards.

Lenses:

A lens is a curved portion of a reflective substance such as glass or plastic that is curved on both sides. Lenses differ from mirrors in that they only have one side with a reflecting surface. A lens can be classified into one of the following categories based on its shape:

• A lens that curves outwards is referred to as a convex lens. It's thicker in the middle and gets thinner as it gets closer to the edges. At a particular point, it blends the light rays going through it. As a result, it's also known as a Converging Lens.

• Concave Lenses are inwardly curved lenses. It has a thinner centre and larger margins. It refracts the light that passes through it in a variety of directions. As a result, it's also known as a Diverging Lens.

What is a Rainbow in the Sunlight?

A rainbow is a natural phenomenon that occurs when the sun's light is reflected and refracted by water droplets in the atmosphere. A rainbow is a band of seven colours that appears in the sky as an arc — red, orange, yellow, green, blue, indigo, and violet.

This also indicates that the sun's white light contains seven different coloured lights that separate owing to refraction (called a Spectrum of Lights). The following diagram depicts the white light spectrum: Rainbows, soap bubbles, the surface of a CD, and prisms are just a few examples.

Newton's Disc: 

To make Newton's disc, divide a disc into seven segments and paint each of them with the rainbow's seven colours. When the disc is turned quickly in daylight, all of the colours tend to blend, giving the disc a white appearance.

Tips to Excel CBSE Class 7 Science:

• Have the correct attitude: When you're excited to learn about a topic, studying becomes a fun pastime. When you are confident in the concepts you've learned and have completed numerously solved practise questions, preparing for a test or exam becomes a lot easier. Knowing why you're learning something makes it easier to understand.

• Collect the necessary resources: All you need to prepare for your Class 7 exams is NCERT books and askIITians study material, exam papers, and NCERT solutions. We provide you with the greatest tutors in India, as well as an online Test Series and an active Q&A forum where you can get quick answers to all of your questions and concerns.

• Create a conducive learning environment: To study, get a comfy workstation and chair. Make sure you're getting enough light that isn't too harsh on your eyes. To avoid being too cold or too overheated when studying, dress appropriately for the season. If the temperature is a little cooler, though, you may be able to stay awake and concentrated for longer.

• Distract yourself as little as possible: Experts at Vedantu advise that you study in a separate room or a corner facing the wall. If necessary, noise-cancelling headphones can be used to block out the noise. Some pupils find that listening to soft instrumental music helps them concentrate on what they're reading.

Class 7 Online Coaching at Vedantu

According to the New Education Policy, Class 7 is the second year of middle school in the Indian education system (NEP). Vedantu provides CBSE online coaching to kids in Class 7 and views it as a warm-up time for STEM (Science, Technology, Engineering, or Mathematics) hopefuls. We recognise that Class 7 is a critical stage in a student's development of an interest in disciplines such as physics, mathematics, biology, and chemistry. As a result, the Vedantu CBSE Class 7 materials go through all of the principles and topics in great detail and clear, easy-to-understand terms.

Vedantu was the first to offer online school coaching programmes. To provide the best learning experience for Class 7 pupils and solutions for free, we have excellent and trained professors, awesome and specialised digital content, and the most up-to-date infrastructure. Get in touch with us right away to find out how we can help you boost your marks in class.