UGC NET JRF November 2020 Paper-2
November 28, 20232018 July 22 NTA UGC NET Paper 1
November 28, 2023Question 10168 – GATE 2020
The figure below shows an annular ring with outer and inner radii as b and a, respectively. The annular space has been painted in the form of blue colour circles touching the outer and inner periphery of annular space. If maximum n number of circles can be painted, then the unpainted area available in annular space is ______.
Correct Answer: A
Question 3 Explanation:
Area of non-painted between 2 circles area of part 1 = πb2 – πa2 = π(b2 – a2)
Radius of painted circles = b-a/2
Area of painted circle = π(b-a/2)2
For n circles = nπ(b-a/2)2
Non-painted area = π[b2 – a2– n/4(b – a)2]
π[(b2 – a2) + π/4(b – a)2]
π[(b2 – a2) – π/4(b – a)2]
π[(b2 – a2) – n(b – a)2]
π[(b2 – a2) + n(b – a)2]
Subscribe
Login
0 Comments