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What is mirror, types of mirror and mirror formula class 10th science numerical

What is mirror?

A mirror is a reflective surface that bounces off light, producing either a real image or a virtual image.

Types of mirror

 Mirrors are mainly three types are plane mirrors and concave and convex mirrors.

Concave mirror :-  If the inner side of the spherical mirror is reflecting, it is called a concave mirror. 

Convex Mirror : If the outer side of the spherical mirror is reflecting, it is called a convex mirror.

Characteristics of the image formed by a plane mirror. 

(i) The Image is erect. 

(ii) The Image is of the same size as that of the object. 

(iii) The image is laterally inverted. Right side appears to be left and left side appeared to be right. 

(iv) The image is virtual.

Reflection and refraction of light lens formula Class 10th science Numerical

Lens :- A transparent material bound by two surfaces, of which one or both surfaces are spherical is called the lens.

There are two types of lenses:

i. Convex (Converging) lens- Convex lenses are thick in the middle and thinner at the edges. A convex lens is also known as the converging lens because it converges parallel light rays inwards to a point known as the focal point.

ii. Concave (Diverging) lens- Concave lenses are flat in the middle and thicker at the edges. The concave lens is also known as a diverging lens because it diverges the parallel light rays outward from a point knows as the focal point.

Lens formula:

If u = object distance, v = image distance and

f = focal length of lens,then the lens formula is given by

According to sign conventions we need to assume the distance as follows,

Object distance, u= -ve , Image distance, v = -ve/+ve (depends upon the position of image) and Focal length, f= -ve for concave lens/+ve for convex lens.

 

Let’s consider following example to understand this formula more precisely.

Ex.1) An object is kept in front of converging lens of focal length 20 cm at distance of 10 cm. Find position of image, nature of image.

Solution: Data given ;( using all sign conventions)

Focal length, f= +20 cm

Object distance, u= -10 cm

Image distance=?

Formula:

On substituting the above values, we get

∴ 1/v = 3/20

∴ v = 20/3

∴ v = 6.67 cm

Positive value of ‘v’ indicates that image is real but inverted.

Magnification by lenses (M):

Magnification is defined as the ratio of height of image (h₂) to the height of object (h₁) or the ratio of image distance (v) to object distance (u).

Ex.2) An object of height 5 cm kept in front of convex lens of focal length 25 cm at distance of 10 cm. Find position of image, nature of image and height of the image.

Solution: Data given ;( using all sign conventions)

Height of object, h₁= + 5 cm

Focal length, f= +25 cm

Object distance, u= -10 cm

Image distance=?

Image height=?

Formula:

∴ 1/v = 35/200

v = 200/35

∴ v = 5.7 cm

Positive value of ‘v’ indicates that image is real but inverted.

Now to calculate height of image use 2^nd formula

Hence the height of image obtain here will be 2.85 cm.

(3) The distance of object is 20cm from convex mirror of focal length is 25 cm. Find the position of image?

Given:

F = 15 => convex mirror

Object distance u = -20 cm

Image distance (v) =?

1/f = 1/v + 1/u

1/25 = 1/v + 1/-20

1/25 + 1/20 = 1/v

45/500 = 1/v

V = 500/45 = 11.11

V = 11.1100

The value of  V is +ve so image is virtual.

(4) The radius of curvature is 38 cm. Find the focal length of convex mirror?

Given:

R = 38 cm

Focal length is equal to half of radius of curvature

Focal length = R/2

= 28/2

F = 19 cm

Focal length is 19 cm

(5) Find the position of image if the focal length of convex lens (f) is 8 cm and object is placed 16 cm from lens.

Given:

f = 8 cm

u = – 16 cm

v =?

1/f = 1/v – 1/u

1/8 = 1/v – 1/16

1/v = 1/8 – 1/16

1/v = 1/16

V = 16 cm

∴ The image is placed 16 cm from the principal axis.

Chemical Names and Common Name of Chemical Formula in Hindi

 Chemical Names and Common Name of Chemical Formula
रासायनिक सूत्रो के रासायनिक नाम व सामान्य नाम

सामान्‍य नाम	रासायनिक यौगिक	रासायनिक सूत्र
ब्लीचिंग पाउडर	कैल्शियम ऑक्‍सीक्‍लोराइड	CaOCL2
चाक (संगमरमर)	कैल्शियम कार्बोनेट	CaCo3
बेकिंग पाउडर	सोडियम बाइकार्बोनेट	NaHCO3
पोटाश एलम	पोटेशियम एल्युमिनियम सल्फेट	KAl(SO₄)₂·12H₂O
नीला थोथा	कॉपर सल्फेट	CuSO4.xH2O
बुझा चूना	कैल्शियम हाइड्रॉक्साइड	Ca(OH)2
त्वरित चूने	कैल्शियम ऑक्साइड	CaO
क्लोरोफॉर्म	ट्राइक्‍लोरो मीथेन	CHCl3
कास्टिक सोडा	सोडियम हाइड्रॉक्‍साइड	NaOH
कास्टिक पोटाश	पोटेशियम हाइड्रॉक्‍साइड	KOH
शुष्‍क बर्फ	ठोस कार्बन डाइ आक्‍साइड	CO2
सिरका	एसिटिक एसिड	CH3COOH
धावन सोडा	सोडियम कार्बोनेट	Na2CO3
प्लास्टर ऑफ पेरिस	कैल्शियम सल्फेट	CaSO4. 1/2 H2O
एप्‍सम	मैग्नीशियम सल्फेट	MgSo4
जिप्सम	कैल्शियम सल्फेट	CaSo4. 2H2O
भारी जल	ड्यूटेरियम ऑक्साइड	D2O
हरा थोथा	फेरस सल्फेट	FeSo4
मोहर लवण	अमोनियम फेरस सल्फेट	(NH4)2Fe(SO4)2·6H2O
सफेद थोथा	जिंक सल्फेट	ZnSo4.7H2O
मार्श गैस	मीथेन	CH4
रेत	सिलिकॉन ऑक्साइड	SiO2
मैग्नीशिया	मैग्नीशियम ऑक्साइड	MgO
हँसाने वाली गैस	नाइट्रस ऑक्साइड	N2O
वरमेलियम	मरक्‍यूरिक सल्फाइड	HgS
चीनी	सुक्रोज	C12H22O11
T.N.T.	ट्राइनाइट्रो टाइलून	C7H5N3O6

भारत में शास्त्रीय भाषाओं को शास्त्रीय भाषा का दर्जा प्रदान किया गया

भारत में शास्त्रीय भाषाएँ

वर्तमान में छ: भाषाओं को वर्ष 2004- 2014 तक शास्त्रीय भाषा का दर्जा प्रदान किया गया जो इस प्रकार हैं-

• तमिल (2004)
• संस्कृत (2005)
• कन्नड़ (2008)
• तेलुगू (2008)
• मलयालम (2013)
• ओडिया (2014)