Chapter 15- Light Class 7 science- Question and Answer (Fill in the Blanks)

Chapter 15- Light -Question and Answer (Fill in the Blanks) – Solved Worksheet with Explanation

• Question- Light is a form of _______ that enables us to see our surroundings.
• Answer- Energy
• Explanation- Light is described as a type of energy that is crucial for visual perception, allowing us to see objects and environments around us.

• Question- In the experiment with a candle and pipes, the flame is not visible through the _______ pipe.
• Answer- Bent
• Explanation– The experiment demonstrates that light travels in a straight line. The bent pipe obstructs the straight path of light, making the candle flame invisible.

Also Check Class 7 Science -Chapter 15 – Light- Complete Notes

• Question- _______ objects are materials through which no light can pass.
• Answer- Opaque
• Explanation- Opaque objects, like a table or a book, block all light from passing through, hence completely blocking the view of anything behind them.

• Question- The process where light hitting an object is not absorbed but rather thrown back from the surface is called _______.
• Answer- Reflection
• Explanation- Reflection of light occurs when light, instead of being absorbed, is thrown back by the surface it encounters.

• Question- Plane mirrors reflect light in a manner that the angle of _______ equals the angle of reflection.
• Answer- Incidence

• Explanation- In plane mirrors, the angle at which light hits (angle of incidence) is equal to the angle at which light is reflected back.
• Question- Image formation through mirrors can either be a real image or a _______ image.

• Answer: Virtual
• Explanation: Images formed by mirrors can be real (formed by actual convergence of light rays) or virtual (formed by apparent convergence of diverging light rays).
• Question- The incident ray is the beam of light that _______ a reflecting surface.
• Answer- Approaches and strikes
• Explanation- The incident ray is defined as the light beam that comes from a light source and hits the reflecting surface.
• Question- The angle between the incident ray and the normal is called the _______.
• Answer- Angle of Incidence
• Explanation- The angle of incidence is measured from the normal to the direction of the incoming ray.
• Question- In the law of reflection, the angle of incidence is always _______ to the angle of reflection.
• Answer- Equal
• Explanation- This law states that the angle of incidence (∠i) is always equal to the angle of reflection (∠r), irrespective of the angle at which light hits the surface.
• Question- The image formed by a plane mirror is always a _______ image.
• Answer- Virtual
• Explanation- Plane mirrors create virtual images, which cannot be projected onto a screen and appear to be behind the mirror.
• Question- Lateral inversion is the phenomenon where the right side of the object appears as the _______ side in the image.
• Answer- Left
• Explanation- Lateral inversion causes a reversal in the orientation of the image, making the right side appear as the left and vice versa.
• Question- For an observer to see their entire image in a plane mirror, the mirror must be at least _______ the height of the observer.
• Answer- Half
• Explanation- To view one’s entire image, the plane mirror must be at least half the height of the observer.
• Question- Concave mirrors can form real, inverted, and _______ images.
• Answer- Magnified
• Explanation- Concave mirrors have the ability to form images that are real, inverted, and magnified, depending on the object’s distance from the mirror.
• Question- Convex mirrors always form images that are virtual, ______, and diminished.
• Answer- Erect
• Explanation- Convex mirrors consistently produce images that are virtual, erect (upright), and smaller (diminished) than the actual object.
• Question- Newton discovered that white light is a mixture of ______ different colours.
• Answer- Seven
• Explanation- Sir Isaac Newton demonstrated that white light comprises seven different colours, which become evident when white light passes through a prism.
• Question- In diffused reflection, light rays are reflected back in various directions _______.
• Answer- Irregularly
• Explanation- Diffused reflection occurs on rough surfaces and results in light rays being reflected in multiple, irregular directions.
• Question- Regular reflection occurs on _______ and shiny surfaces.
• Answer- Smooth
• Explanation- Smooth and shiny surfaces, like mirrors, exhibit regular reflection where light rays are reflected back uniformly.
• Question- The formation of rainbows involves both refraction and _______ within the raindrops.
• Answer- Reflection
• Explanation- Rainbows are formed when sunlight undergoes both refraction (bending) and reflection inside raindrops, creating the colourful arc.
• Question- In satellite dishes, _______ mirrors are used to gather and reflect signals.
• Answer- Concave
• Explanation– Concave mirrors are employed in satellite dishes because they can focus signals to a specific point, which is crucial for signal reception.
• Question- Convex mirrors provide a _______ field of view in vehicle mirrors.
• Answer- Wider
• Explanation- Convex mirrors are used in vehicle mirrors due to their ability to offer a wider field of view, enhancing driving safety.
• Question- Magnifying glasses typically use _______ lenses to enlarge the appearance of objects.
• Answer- Convex
• Explanation- Convex lenses are utilised in magnifying glasses as they can magnify objects by converging light.
• Question- The word “AMBULANCE” is often written in reverse to utilise the phenomenon of _______ inversion.
• Answer- Lateral
• Explanation- Lateral inversion in plane mirrors causes the reversed text to appear correctly when viewed in a rearview mirror, helping in quick identification of emergency vehicles.
• Question- Concave lenses are used in corrective eyewear to correct _______.
• Answer- Nearsightedness
• Explanation- Concave lenses diverge light rays before they enter the eye, making them suitable for correcting nearsightedness.
• Question- To see their entire image in a plane mirror, the mirror must be at least _______ the height of the observer.
• Answer- Half
• Explanation- A plane mirror needs to be at least half the height of the observer to show their entire image because the image is of the same size as the object.