When a slide is placed 15 cm behind the lens in a projector, an image is formed at 3 infront of the lens. (i) Show the image formation by a ray diagram. (ii) Find the focal length of the lens. (iii) What will be the distance between the lens and the slide in order to get and image at a distance 4 metre from the lens ? (iv) Determine the magnification for the case (iii).
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A smooth block is released at rest on a `45^(@)` inclined and then slides a distance d. the time taken to slide is n times as much to slide on rough i
`t_(1)=sqrt((2d)/(g sin45^(@)))=sqrt((2d)/((g)/sqrt(2)))` `t_(2)=sqrt((2d)/(((g)/(sqrt(2))-mu(g)/(sqrt(2))))` `t_(2)=nt_(1)` `sqrt((2d)/(((g)/(sqrt(2))-mu(g)/(sqrt(2)))))=nsqrt((2d)/((g)/(sqrt(2))))` `(1)/(sqrt(1-mu))=n` `(1)/(1-mu)=n^(2)` `1 = n^(2)-n^(2)mu` `(1)/(n^(2))=-1-mu` `mu=(1-(1)/(n^(2)))`
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An X-ray tube has nickel as target. The wavelength difference between the ka X-ray and the cut-off wavelength of continuous X-ray spectrum is 84 pm. F
Correct Answer - `14.8 kV`
2 Answers 1 views
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Correct Answer - (a) 320 cm (b) `(1)/(3)cm`
2 Answers 1 views
An object is placed `12 cm` to the left of a diverging lens of focal length `-6.0 cm.` A converging lens with a focal length of `12.0 cm` is placed at
Correct Answer - 8 cm
2 Answers 1 views
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Correct Answer - 1.48
2 Answers 7 views
A concave mirror forms a real image four times as tall as the object placed 10 cm infront of mirror. Find the position of the image and the radius of
Correct Answer - 40 cm in front of the mirror, `R =- 16 cm`
2 Answers 1 views
An object is 60 cm in front of a thin lens, the image being 300 cm on the other side of the lens. Calculate the displacement of the image, when the ob
Correct Answer - 500 cm
2 Answers 2 views
A source of light and a screen are placed 90 cm apart. Where should a convex lens of 20 cm focal length be placed in order to form a real image of the
Correct Answer - 60 cm or 30 cm from the source
2 Answers 2 views
A concave lens is placed in the path of convergent rays. The rays are focussed on the axis 15 cm behind the lens. Where would these rays have been foc
Correct Answer - At a distance of 10 cm behind the lens
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Find the focal length and power of a convex lens, which when placed in contact with a concave lens of focal length `25 cm` forms a real image `5` time
Correct Answer - 10 cm, 10D
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