Mehapatel

Calculation of focal length and power of correcting lens in myopia: Let x be the distance of the actual far point from the eye (distance from the concave lens placed near the eye).∴ Object distance or far point of the eye, u = – ∞Image formed, v = – x,Focal length, f =?Using lens formula,               1f = 1v-1u      = 1-x-1-∞       = -1x+0      = -1x. ∴   Required focal length, f = -x Required power, P = 1f =-1x Since the power is negative, this implies that the correcting lens is a concave lens.

i)  Dipole moment of dipole is given by,  i) 
Force on –q at A = -qE
Force on +q at B = + qE
So,
Net force = qE – qE = 0 
ii) Work done on dipole is given by, 

The objective of physical education is the development of an individual mentally, socially and emotionally fit. Through participation in adventurous sports, following objectives can be achieved.
To develop self-confidence: By overcoming the fear and experiencing the thrill one can develop self confidence.
To build the concentration: In these sports a person has to be very alert and attentive all the time. It develops the concentraition.
To develop mental and physical fitness: These sports help in developing the mental and physical fitness. Such sports fitness skills like jumping, climbing 

भारत के भू-आकृतिक विभाग निम्नलिखित है-हिमालय पर्वतउत्तरी मैदानप्रायद्वीप पठारभारतीय मरुस्थलतटीय मैदानहिमालय क्षेत्र तथा प्रायद्वीप पठार के उच्चावच लक्षणों में अंतर इस प्रकार है-
हिमालय
प्रायद्वीपीय पठार

(i) हिमालय भारत की उत्तरी सीमा पर स्थित है। (ii) यह बहुत ऊँची पर्वतीय दीवार बनता है।(iii) उत्तर-दक्षिण में हिमालय पर्वत की तीन श्रंखलाएँ है-हिमांद्री, हिमाचल, शिवालिक।(iv) पूर्व-पश्चिम हिमालय में पंजाब हिमालय, कुमाऊँ, नेपाल हिमालय, असम हिमालय शामिल है।(v) माउंट एवरेस्ट, कंचनजुंगा धौलागिरी आदि विश्व के सबसे ऊँचे शिखर है जो हिमालय में स्थित है। इनमे से कुछ 8,000 मीटर ऊँचे है।(vi) हिमालय के

To convert from Propene to Propan-2-ol, the addition of H2SO4 takes place in accordance with Markovnikov ‘s  rule i.e.

Answer :- Copper (1) sulphide (CuS) .......In the extraction of copper from its sulphide ore, when ore is subjected to roasting, some of it is oxidised to Cu,0
‘which reacts with the remaining Cu,S (sulphide ore) to give copper metal.
CUS +2Cu0 — 6Cu +S0, 1
In this process, Cu,S behaves as reducing agent.
In the extraction of copper from its sulphide ore, when ore is subjected to roasting, some of it is oxidised to Cu,0
‘which reacts with the remaining Cu,S (sulphide ore) to give copper metal.
CUS +2Cu0 — 6Cu +S0, 1
In this process, Cu,S behaves as reducing agent.

Answer :-

B. ML2/12

Since rod is bent at the middle, so each part of it will have same length (L/2) and mass (M/2)
as shown,

Mandela said that a man who takes away another man’s freedom is a prisoner of hatred because he himself is a victim of prejudice and narrowmindedness. He justified it by saying thought a man is not free if his freedom is taken away from him. Likewise, if he is taking away someone else’s freedom, he is not truly free.

चाय एक अत्यंत महत्वपूर्ण पेय फसल है। इसे शुरुआत में अँगरेज़ भारत लाये थे, परन्तु आज ज़्यादातर चाय बागानों के मालिक भारतीय ही हैं। चाय का पौंधा उष्ण और उपोष्ण कटिबंधीय जलवायु, जीवांश युक्त गहरी मिट्टी तथा सुगम जल निकास वाले ढलवाँ क्षेत्रों में भलीभाँति उगाया जाता है। चाय की झाड़ियों के लिए वर्ष भर कोष्ण और पालारहित जलवायु की आवश्यकता होती है। वर्ष भर सामान रूप से होने वाली वर्षा की बोछारें इसकी कोमल पत्तियों के विकास में सहायक होती है।आज भारत विश्व का अग्रीण चाय उत्पादक और निर्यातक देश है।

Evelyn was Seventeen years old when she went to the Royal Academy of Music in London.

Loan capital of company

Business risk implies uncertainty of profits or danger of loss or continuity of business due to some unforeseen events.It refers to the chance of loss on account of unfavourable or unpredictable happenings.With every risk there is a possibility of loss which may or may not be measurable and the person or organization exposed to the risk may or may not be aware of the possibility of loss.Business enterprises constantly face two types of risk:
(i) Speculative
(i) Pure
Speculative risks involve both the possibility of gain as well as the possibility of loss. Pure risks involve only the possib

કોઈ અણ દેશની વસ્તીનીતિના નિર્ધારણમાં જન્મદરના આંકડાઓ મહત્વ ધરાવે છે. જન્મદર એટલે દર હજારની વસ્તીએ વર્ષ દરમિયાન જન્મેલાં કુલ બાળકો દ્વારા વસ્તીમાં કેટલો વધારો થયો તે દર્શાવે છે. ભારતમાં જન્મદરનું પ્રમાણ નીચે દર્શાવેલ છે :ભારતમાં જન્મદરનું પ્રમાણ સતત ઘટતું ગયું છે. ભારત સરકારના કુટુંબનિયોજનના કાર્યક્રમોને લોકો દ્વારા સ્વીકૃતિ મળી. શહેરી વિસ્તારોની સરખામણીમાં ગ્રામીણ વિસ્તારોમાં જન્મદરનું પ્રમાણ ઉંચું જોવા મળે છે. તેનાં મુખ્ય કારણો નીચે પ્રમાણે છે :1. યોગ્ય આરોગ્યવિષયક સુવિધાઓનો અભાવ, 2. ગરીબી, 3. બેકારી, 4.નાની ઉંમરે લગ્ન કરવાનો રિવાજ વગેરે.

Escape velocity is minimum velocity with which a body must be thrown upward so that it may just escape.Expression for escape velocity:Let a body of mass m be escaped from gravitational field of the earth. During the course of motion, let at any instant body be at a distance r from the centre of the earth.The gravitational force between body and the earth is,                               and work done to raise the body by distance dr is,                                Total work done W in raising the body from the surface of the earth to infinity is,                                          

Curdy white ppt. observed which is soluble in NH4OH

(a) (i) ∆364-957744
(ii) The temple at Rampura = 954806
(b) Two features seen in the map which show that the region has seasonal rainfall:
(i) Seasonal rivers and streams
(ii) Broken ground.
(c) Distance in cm = 4.8 [Scale (2 cm = 1 km)]
Distance in km = 4.8/2 = 2.4 km.
(d) Chief form of irrigation is perennial lined well which is evidence as many blue dots can be seen in the map.
(e) Streams in 9478 do not join a river because these are disappearing streams, which dry up or disappear into the sand.
Another grid square is 9575.
(f) (i) Black broken line in 9575 represents disappeari

Wavefront is defined as the locus of all the points in space that reach a particular distance by a propagating wave at the same instant.Huygen s principle:i) Each point of the wavefront is the source of a secondary disturbance and the wavelets emanating from these points spread out in all directions. These travel with the same velocity as that of the original wavefront.ii) The shape and position of the wave-front, after time t , is given by the tangential envelope to the secondary wavelets.A plane wavefront is incident on a thin convex lens:                                                   

Since, the tangent at any point of a crcle is perpenedicular the radius throgh the point of contact.∴ ∠OAT = 90°and ∠OBT = 90°If two tangents are drawn to a circle from an external point, then they are equally inclined to the segment joining the centre to the point∴ ∠ATO = ∠BTOBut ∠ATO = 40°Now, ∠BTO = 40°In quadrilateral, ∠OBT, we have∠OAT + ∠OBT + ∠ATB + ∠AOB= 360°⇒ 90 + 90 + 80 + ∠AOB = 360°⇒ 260 + ∠AOB = 360°⇒ ∠AOB = 360° – 260° = 100°

Given, wavelength of the photon,  = 275 nm
Energy of the photon is given by,  
This corresponds to transition B as from the figure.
i)     For maximum wavelength  should be minimum. Minimum energy corresponds to transition A.
ii) For minimum wavelength,  should be maximum. Maximum energy corresponds to transition D.

Cross-aldol condensation: Aldol conden-sation of a mixture of two different aldehydes or ketones each containing an α-hydrogen gives a mixture of four products. Two products are made up of two molecules of same carbonyl compounds and are same as in case of simple aldol condensation. The other two products arise from the reaction between one molecule each of two different carbonyl compounds. These are called cross aldol conden-sation products and the reaction leading to formation of these products is known as cross-aldol conden-sation. Example: