The resolving power of an astronomical telescope can be significantly increased by:
A. Decreasing the focal length of the eyepiece.
B. Using light of a longer wavelength.
C. Increasing the focal length of the objective lens.
D. Increasing the aperture (diameter) of the objective lens.
Answer: Option D
Solution (By JKSSB Mock Tests)
Resolving power is a telescope's ability to distinguish closely spaced objects (like double stars) as separate. It is proportional to D / lambda, where D is the diameter (aperture) of the objective lens and lambda is the wavelength of light. Increasing the aperture D directly and strictly increases the resolving power.
Explanation:
At maximum height, final velocity v = 0. Using v = u - gt (taking upward positive), 0 = u - gt ⇒ t = u/g. This is time of ascent. Total time of flight would be 2u/g. The equation derives from Newton's first equation of motion under constant acceleration g downward. Memory aid: Time to peak = initial velocity / gravitational acceleration. This fundamental result appears in projectile motion problems. Competitive exams often combine this with energy conservation or symmetry concepts for advanced questions.
Explanation:
The Stefan-Boltzmann law dictates that the total energy radiated per unit surface area of a black body across all wavelengths per unit time (Emissive Power, E) is strictly directly proportional to the fourth power of the black body's thermodynamic (absolute) temperature. E = sigma * T^4, where sigma is the Stefan-Boltzmann constant.
Explanation:
Potential difference V = W/q: work per unit charge. Electric field E = F/q: force per unit charge. Memory tip: 'Potential = work/charge (scalar); Field = force/charge (vector)'. Electrostatics definition frequently tested in competitive exams.
No comments yet. Be the first to start the discussion!