Doubtly
@Doubtly · Joined Feb 2021
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- Which one of the following type of resource is iron ore? (a) Renewable (b) Biotic (c) Flow (d) Non-renewable Correct option is d) Non-renewable Explaination:: iron ore is non-renewable resource 1
- Consider a circular coil of wire carrying current I, forming a magnetic dipole. https://www.youtube.com/watch?v=Ui0b0NZ0MBc&ab_channel=PencilJee 2
- How to write math formulas while asking the question on This Website ? While asking a question if you want to add math formulas , you can use latex https://www.overleaf.com/learn/latex/Learn_LaTeX_in₃0_minutes T... 1
- Describe the importance of himalayas Importance of Himalayas: The Himalayas acts as a barrier protecting the great Plains of India from the cold winds of Central Asia during the... 2
- A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Power of lens, P= 1/f P= 1.5D f= 1/1.5 = 10/15 = 0.66 m A convex lens has a positive focal length. Hence, it is a convex lens or a convergin... 1
- Find the focal length of a lens of power -2.0 D. What type of lens is this? Power of lens, P= 1/f P= -2D f= -1/2 = -0.5 m A concave lens has a negative focal length. Hence, it is a concave lens. 1
- An object of size 7.0 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. https://www.youtube.com/watch?v=meqKmlYN_p8&ab_channel=2Piclasses An object of size 7.0 cm is placed at 27 cm in front of a concave mirror o... 2
- An object 5 cm is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. https://youtu.be/Axatke6lD44 2
- The magnification produced by a plane mirror is +1. What does this mean? The positive sign means image formed by a plane mirror is virtual and erect. Since the magnification is 1 it means that the size of the imag... 1
- An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of the image. https://yo... 2
- A concave lens of focal length 15 cm forms an image 10 cm from the lens. How far is the object placed from the lens? A concave lens of focal length 15 cm forms an image 10 cm from the lens. How far is the object placed from the lens? Draw the ray diagram. h... 2
- An object 5 cm in length is held 25 cm away from a converging lens of focal length 10 cm. An object 5 cm in length is held 25 cm away from a converging lens of focal length 10 cm. Draw the ray diagram and find the position, size a... 2
- One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? The convex lens will form complete image of an object, even if its one half is covered with black paper. It can be understood by the followi... 1
- Name the type of mirror used in the following situations. (a) Headlights of a car a) Concave Mirror: This is because concave mirrors can produce powerful parallel beam of light when the light source is placed at their prin... 1
- We wish to obtain an erect image of an object, using a concave mirror of focal length 15 cm. Range of the distance of the object = 0 to 15 cm from the pole of the mirror. Nature of the image = virtual, erect and larger than the objec... 1
- Which of the following lenses would you prefer to use while reading small letters found in a dictionary? c) A convex lens of focal length 5 cm 2
- No matter how far you stand from a mirror, your image appears erect. The mirror is likely to be d) either plane or convex 2
- A spherical mirror and a thin spherical lens have each a focal length of -15 cm. The mirror and the lens are likely to b a) both concave 2