1.the angle between an incident ray and the plane...8. a convex lens of focal length 10 cm is placed...

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Page 1: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 2: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

1.The angle between an incident ray and the plane mirror is 30o. The total angle between the incident ray and reflected ray will be:एक आऩतन ककयण औय सभतर दऩपण के फीच का कोण 30o है। आऩतन ककयण औय ऩयावर्तपत ककयण के फीच का कुर कोण होगा:a) 30o

b) 60 o

c) 90 o

d) 120 o

Page 3: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 4: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

2.A ray of light is incident on a plane mirror making an angle of 90o with the mirror surface. The angle of reflection for this ray of light will be:दऩपण की सतह के साथ 90o के कोण ऩय सभतर दऩपण ऩय प्रकाश की एक ककयण की आऩर्तत होती है। प्रकाश की इस ककयण के लरए ऩयावतपन कोण होगा:a) 45o

b) 90o

c) 0o

d) 60o

Page 5: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 6: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

3. If the radius of curvature of a spherical mirror is 20 cm, what is the focal length? मदद एक गोराकाय दऩपण की वक्रता की त्रिज्मा 20 सेभी है, तो पोकर रॊफाई क्मा है?

Page 7: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

Thus, the focal length of this spherical mirror is 10 cm. इस प्रकार, इस गोलाकार दर्पण की फोकल लंबाई 10 सेमी है।

Page 8: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

4.Find the size, nature and position of image formed when an object of size 1 cm is placed at a distance of 15 cm from a concave mirror of focal length 10 cm. आकाय, प्रकृर्त औय छवव की स्थथर्त का ऩता रगाएॊ जफ 1 सेंटीभीटय की वथतु पोकर रॊफाई 10 सेभी के अवतर दऩपण से 15 सेभी की दयूी ऩय यखी जाती है।

Page 9: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

Here we have been given the object distance and focal length, so first of all we will find out the image distance which will give us the position of image महाॊ हभें वथतु की दयूी औय पोकर रॊफाई दी गई है, इसलरए सफसे ऩहरे हभ छवव की दयूी का ऩता रगाएॊगे जो हभें इभेज की स्थथर्त प्रदान कयेगी

Page 10: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 11: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 12: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

(ii) Nature of image. Since the image is formed in front of the concave mirror , its nature will be “Real and inverted”.छवव की प्रकृर्त- चूॊकक छवव अवतर दऩपण के साभने फनती है, इसलरए इसका थवरूऩ "वाथतववक औय उल्टा" होगा।

Page 13: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 14: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 15: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

Thus, the size of image is 2 cm long. The minus sign here shows that the image is formed below the principal axis. That is, is a real and inverted image. इस प्रकाय, छवव का आकाय 2 सेभी रॊफा है। महाॊ भाइनस साइन से ऩता चरता है कक इभेज वप्रॊलसऩर एस्क्सस के नीचे फनाई गई है। मह एक वाथतववक औय उरटी छवव है।

Page 16: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 17: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 18: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 19: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 20: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 21: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

6. A concave mirror produced three times magnified (enlarged) real image of an object placed at 10 cm in front of it. Where is the image located? एक अवतर दऩपण ने उसके साभने 10 सेभी ऩय यखी एक वथतु की वाथतववक छवव को फढाते हुए तीन गुना (फढे हुए) ककमा। छवव कहाॉ स्थथत है?

Page 22: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 23: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 24: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed as to form its real image on the wall?एक दीवाय से 12 सेभी की दयूी ऩय नाक की रॊफाई 10 सेभी का उत्तर रेंस यखा गमा है। दीवाय ऩय अऩनी वाथतववक छवव फनाने के लरए रेंस से ककतनी दयूी ऩय एक ऑब्जेक्ट होना चादहए?

Page 25: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 26: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 27: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

Thus, the object should be placed at a distance of 60 cm in front of the convex lens. The minus sign shows that the object is on the left side of the lens. इस प्रकाय, वथतु को उत्तर रेंस के साभने 60 सेभी की दयूी ऩय यखा जाना चादहए। भाइनस साइन से ऩता चरता है कक ऑब्जेक्ट रेंस के फाईं ओय है।

Page 28: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

9. If an object of 7 cm height is placed at a distance of 12 cm from a convex lens of focal length 8 cm, find the position, nature and height of the image.मदद 7 सेभी ऊॊ चाई की वथतु को पोकर रॊफाई 8 सेभी के उत्तर रेंस से 12 सेभी की दयूी ऩय यखा गमा है, तो छवव की स्थथर्त, प्रकृर्त औय ऊॊ चाई का ऩता रगाएॊ।

Page 29: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 30: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

Thus, the image is formed at a distance of 24 cm from the convex lens. The plus sign for image distance shows that the image is formed on the right side of the convex lens. Only a real and inverted image is formed on the right side of a convex lens, so the image formed is real and inverted. इस प्रकाय, छवव उत्तर रेंस से 24 सेभी की दयूी ऩय फनाई गई है। छवव दयूी के लरए प्रस चचह्न दशापता है कक छवव उत्तर रेंस के दाईं ओय फनाई गई है। उत्तर रेंस के दाईं ओय केवर एक वाथतववक औय उरटी छवव फनती है, इसलरए फनाई गई छवव वाथतववक औय उरटी है।

Page 31: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 32: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed
Page 33: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

10. The magnification produced by a spherical lens is +2.5. What is the:एक गोराकाय रेंस द्वाया र्नलभपत आवधपन +2.5 है।a) Nature of image?/ छवव की प्रकृर्त?b) Nature of lens?/ रेंस की प्रकृर्त?

Page 34: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

Ans. (a) when the magnification is positive, then the image is virtual and erect. In cases, the magnification ahs positive sign, so the nature of image is virtual and erect. (a) जफ आवधपन धनात्भक होता है, तफ प्रर्तत्रफम्फ आबासी औय सीधा होता है। भाभरों भें, आवधपन सकायात्भक सॊकेत देता है, इसलरए छवव की प्रकृर्त आबासी औय खडी होती है।

Page 35: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

(b) The value of magnification give here is 2.5 (which is more than 1). So, the image is larger than the object of magnified. A virtual, erect and magnified image can be formed only by a convex lens; therefore, the nature of lens is convex. महाॉ आवधपन का भान 2.5 है (जो 1 से अचधक है)। तो, छवव आवचधपत वथतु से फडी है। एक आबासी, सीधा औय आवचधपत छवव केवर उत्तर रेंस द्वाया फनाई जा सकती है, इसलरए, रेंस की प्रकृर्त उत्तर है।

Page 36: 1.The angle between an incident ray and the plane...8. A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should an object be placed

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