If you are looking for CBSE Class 10 Physics problems based on Concave Mirror, you have arrived at the right spot. Below are all the probable questions that you can study and score good marks in the upcoming CBSE Class 10 exams. Practice them well on pen and paper and revise them regularly to build a strong conceptual understanding.
1. What is a concave mirror?
When a hollowed ball is split into parts, and the exterior surface of each cut portion is painted, it forms a concave mirror that has the inside reflecting the light. A concave mirror is a term for this sort of mirror. Light converges at a spot where it strikes and mirrors off the concave mirror reflecting surface. Due to this, it is also known as a converging mirror.
2. List the characteristics of concave mirrors?
- Concave Mirrors Have the following essential specifications:
- Before reflection, the concave mirror catches and converges the light incident.
- When an object is placed very close to the concave mirror, it creates a virtual and enlarged image.
- As the length between the item and the concave mirror increases, a true image is created, and the picture size shrinks.
- Concave mirrors can create big, tiny, upright, or virtual images.
3. When an object is placed between the mirror’s focus and pole, list some aspects of the picture generated by a concave mirror?
Following are the characteristics of the image formed by the concave mirror:
- Behind the mirror, an image is created.
- It’s amplified and enlarged.
- It’s virtual.
- It’s upright.
4. Define the term concave mirror’s principal focus?
The principal focus of a concave mirror is the point on its principal axis in which all parallel light rays converge after reflecting from the concave mirror. The light beams originating from an object at an unlimited range from the mirror will parallel the major axis. After reflecting from a concave mirror, the rays will merge into the mirror’s focal point.
5. For reflection by concave mirrors, what are the sign conventions?
1. The object is always positioned on the mirror’s left side.
2. All the distances are determined parallel to the principal axis from the mirror’s pole.
3. All lengths determined to the right of the origin (+ x-axis) are positive, while those determined to the left (– x-axis) are negative.
4. Positive distances are determined perpendicular to and above the major axis (along The y-axis).
5. Lengths determined perpendicular to and below the primary axis (along the –y-axis) are considered negative.
6. What is a concave mirror’s principal focus?
It is a location on the principal axis where parallel beams of light meet.
- Discuss why a ray of light going through a concave mirror’s centre of curvature is reflected in the original direction. [Delhi]
- The ray is incident to the mirror along its normal as it passes through the centre of curvature, i= r = 0. As a result, the ray returns to its original location.
7. If a concave mirror produces a magnification of +2, what is the character of the image it produces?
- The presence of a positive magnification indicator implies that the image is virtual, upright, and magnified.
8. A concave mirror’s image is formed to be virtual, upright, and bigger than the original. So, where would you put the object?
(a) In between primary focus and the curvature’s centre
(b) In the curvature’s centre
(c) Beyond the curvature’s centre
(d) Between both the mirror’s pole and its main focus
(e) Between the mirror’s pole and its main focus.
9. On a screen, a concave mirror magnifies a picture three times. How distant is the screen from the object if it is 210cm in front of the mirror?
The following data (in Cartesian sign convention):
image distance, v
magnification, m = -5
object distance, u = -10cm
We get m = -v/u using the magnification formula.
v = -mu = – (-5) (-10) cm = -50cm
As a result, |v-u| = |-40cm| = 40cm is the distance between the screen (picture) and the item.
10. Describe the image formation by concave mirrors when the object is placed at infinity, beyond the centre of curvature, between the focus and centre of curvature, at focus, between focus and the pole of the mirror.
- When the object is placed at infinity
The mirror reflects two rays that originate from the object parallel to the principal axis. The rays merge at the focus after reflecting on producing an image. The image created will be much reduced, real, point size and upside down.
- When the object is placed beyond the centre of curvature
The item emits two rays, one of which is parallel to the principal axis and the other of which moves towards the mirror’s centre of curvature. After reflection, the image is generated between the centre of curvature C and the focus F. The image that is created is diminished, reversed, and real.
- When the object is positioned at the centre of curvature
The object sends out two rays. One ray runs parallel to the principal axis while the other penetrates through the focus. At the centre of curvature, the picture is generated after reflection. The resulting image is the same size as the original; it is real and inverted.
- When the object is placed between the centre of curvature and focus
The object emits two rays. One ray is parallel to the principal axis, while the other crosses through the mirror’s focus. This is the image formed at the mirror’s centre of curvature C. The image is magnified; it is both real and inverted.
- Assertion (A):
After reflection, a ray travelling through the centre of curvature of a concave mirror is reflected again along the same path.
Reason (R): The incident rays fall perpendicular to the mirror’s reflecting surface.
- (a) Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
- Assertion (A): The searchlight mirrors are concave spherical.
Reason (R): The picture created by a concave spherical mirror is always virtual.
- (c) Assertion is true, but Reason is false.
- Assertion (A): Concave mirrors are utilised as make-up mirrors.
(R) Reason: When the face is positioned inside the concave mirror’s focus, the picture of the face is minimized
- A is true, but R is false.
- Assertion (A): An object can only be seen in a concave mirror if placed beyond the mirror’s centre of curvature.
Reason (R): If the object is located outside the focus of a concave mirror, the image generated is actual.
A: Both A and R are right; R is not the correct answer for A.
1. A concave mirror with a 20 cm focal length is set 50 cm away from the wall. How far away from the wall should an object be positioned for its true image to appear on the wall?
2. A concave mirror with a focal length of 15cm is placed 40cm away from an object. What is the distance between the object and the mirror if the object is pushed 20 cm towards the mirror?
3. An object is put 25 cm away from a spherical mirror, and its image is generated at a distance of 5 cm behind the mirror. What is the best way to determine the focal length? Is the mirror concave or convex?
- Convex, 6.25cm
3. A concave mirror with a focal length of 15 cm is used to keep an object in front of. The resulting image is thrice as big as the object. Determine the object’s two probable distances from the mirror.
4. 30 cm in front of a concave mirror with a focal length of 15 cm, a 2 cm object is put. How far away from the mirror should a screen be placed to achieve a sharp image? What kind of image will be generated, and how big will it be? In this scenario, make a ray diagram to show how the image is formed.
- Centre of curvature
- Define and illustrate the following terms related to a concave mirror on a diagram:
(i) Aperture (ii) Curvature Radius
- Illustrate with a ray diagram and describe the placement, apparent size, and nature of the image generated by a concave mirror when the object is positioned in the mirror’s centre of curvature.
- Outline the sign conventions for spherical mirrors reflecting light. Draw a figure and use these norms to calculate the focal length of a concave mirror that produces a three-fold enlarged real picture of an object 20 cm in front of it.
1. Is it possible to tell the difference between convex and concave mirrors without touching them?
Yes, we can tell the difference between convex and concave mirrors without touching them. As we all know, the image generated in a concave mirror is larger than the actual picture. In addition, the size of the image generated in the convex mirror is smaller than the true image. This fundamental feature allows us to spot the distinction between concave and convex mirrors without handling them. Consider the rearview mirror of a car, which is a convex mirror. In this mirror, if we see the picture of an approaching car, we see the entire image, which is reduced in size. Therefore we can claim that this is a convex mirror without touching it. At the same time, because we see larger representations of items through the telescope, we can say without touching them that this is a concave mirror.
2. What are the uses of concave mirrors?
- Concave mirrors in Microscopes: A concave mirror is employed as a condenser at the device’s base. The mirror illuminates only the sample, ensuring that the surrounding region remains dark. The mirror’s alignment can be changed by rotating it. The specimen may be seen with an eyepiece.
- Concave mirrors are used in headlights and torches because the bulb of the headlamp or torch is placed at the focal point of the concave mirror. Light rays appear as parallel light beams in the Headlights and Torches after reflecting in a concave mirror. These reflected beams have great intensity and can propagate vast distances.
- Concave mirrors are found in medical devices. ENT specialists frequently employ concave mirrors in simple diagnostic devices like head mirrors. The configuration offers adequate lighting in the inspection regions, avoiding shadows.
- Dental mirrors: Dentists use concave mirrors to better vision within the mouth.
3. What are the properties of Concave mirrors?
The properties of concave mirrors are as follows:
- When light falls and reflects from the concave mirror reflecting surface, it converges at a point. Hence, it is also called a converging mirror.
- An enlarged and virtual picture can be seen when the converging mirror is close to the item.
- However, as the gap between the item and the mirror grows, the height of the image shrinks, and a real image emerges.
- The picture created by the concave mirror might be tiny or large, and it can be real or virtual.
4. How would the image in a concave mirror form if the object is kept in focus?
A significantly expanded image at infinity is generated when the object is positioned at a concave mirror’s principal focus (F).
Image characteristics: a really large image
Both real and reverse