Exams › JEE Advanced › Physics

The objective lens of a telescope has a diameter of 250 cm. For light of wavelength 600 nm from a distant object, the limit of resolution of the telescope is closest to:

1. 1.5 x 10⁻⁷ rad
2. 2.0 x 10⁻⁷ rad
3. 3.0 x 10⁻⁷ rad
4. 4.5 x 10⁻⁷ rad

Correct answer: 3.0 x 10⁻⁷ rad

Solution

Limit of resolution theta = 1.22*lambda/D. Here lambda = 600 nm = 6x10⁻⁷ m and D = 250 cm = 2.5 m. theta = 1.22*(6x10⁻⁷)/2.5 = 7.32x10⁻⁷/2.5 = 2.93x10⁻⁷ rad, which is about 3.0x10⁻⁷ rad.

Related JEE Advanced Physics questions

• What factor influences the visibility of fringes in an interference pattern?
• When the screen is moved further along the x-axis away from the source, which of the following statements is false?
• In the Young's double slit experiment using a monochromatic light of wavelength λ, the path difference (in terms of an integer n) corresponding to any point having half the peak intensity is
• Using the expression 2d sin θ = λ, one calculates the values of d by measuring the corresponding angles θ in the range 0 to 90°. The wavelength λ is exactly known and the error in θ is constant for all values of θ. As θ increases from 0°:
• Two coherent point sources separated by a distance d = 5 micrometers emit light of wavelength lambda = 2 micrometers in phase. A circular wire of radius R = 20 micrometers is placed symmetrically around the two sources (sources lie along a diameter). Points A and B are at the ends of the diameter along the line joining the sources; points C and D are at the ends of the diameter perpendicular to the line joining the sources. Which of the following is correct?
• Young's double slit experiment is performed in a medium of refractive index mu1 = 4/3. A thin transparent slab of refractive index mu2 = 3/2 and thickness t = 8 micrometers is placed in front of slit S2. The magnitude of the optical path difference (with respect to the liquid medium) at the central point O is:

⚔️ Practice JEE Advanced Physics free + battle 1v1 →