Book Online Demo
Check Your IQ
Try Test

Courses

Dropper NEET CourseDropper JEE CourseClass - 12 NEET CourseClass - 12 JEE CourseClass - 11 NEET CourseClass - 11 JEE CourseClass - 10 Foundation NEET CourseClass - 10 Foundation JEE CourseClass - 10 CBSE CourseClass - 9 Foundation NEET CourseClass - 9 Foundation JEE CourseClass -9 CBSE CourseClass - 8 CBSE CourseClass - 7 CBSE CourseClass - 6 CBSE Course

Q.

Diameter of a plano - convex lens is 6 cm and its thickness at the centre is 3 mm. Then the focal length of the lens, if the speed of light in the material of lens is 2 × 108 m/s

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya

a

7.5 cm

b

15 cm

c

45 cm

d

30 cm

answer is D.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

detailed_solution_thumbnail
Question Image

μ=cv, μ=3 x 1082 x 108=1.5 For plano covex lens

1f=μ-1R, f=Rμ-1 ; R2=r2+R-y2

(∴Neglecting y2)

R=r22y⇒R=9 x 10-42 x 3 x 10-3=0.15 m ; R=15 cm Focal length f=151.5-1=30 cm

Watch 3-min video & get full concept clarity

tricks from toppers of Infinity Learn

Related Blogs
Get ₹ 1 crore* worth scholarship for JEE / NEET / Foundation
Result Producing online coaching for JEE/NEET of south India
Largest All India Test Series for JEE/NEET
Best Books for IIT JEE
Best Books for NEET
score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

Related Blogs
Get ₹ 1 crore* worth scholarship for JEE / NEET / Foundation
Result Producing online coaching for JEE/NEET of south India
Largest All India Test Series for JEE/NEET
Best Books for IIT JEE
Best Books for NEET
whats app icon
Diameter of a plano - convex lens is 6 cm and its thickness at the centre is 3 mm. Then the focal length of the lens, if the speed of light in the material of lens is 2 × 108 m/s