AQA A-Level Physics Astrophysics Course

What type of lens is used for observing the night sky?

What happens to light when it passes from air into a lens?

A convex lens is a type of converging lens

What are components of a ray diagram?

True or False - This ray diagram shows an object between F and 2F

True or False - This image shows a ray diagram of an object at 2F

What are the 3 properties of an image on a ray diagram?

True or False - The image shows The Lens Formula

True or False - Converging lenses must have positive focal lengths, and diverging lenses must have negative focal lengths for the formula to work.

True or False - For the formula to work, distances to real images should be negative and those to virtual images should be positive

True or False - this diagram shows an Astronomical Telescope in normal adjustment

The formula for Angular Magnificatio = fe/f0

Select features which define a reflecting telescope

What are the differences and similarities between reflecting telescopes and Cassegrain Telescopes?

A Cassegrain reflector uses a secondary mirror to direct light rays reflected by the primary mirror through a hole in the primary mirror towards the observer

The Hipparcos satellite used the parallax method to measure the distance to more than 100,000 stars with a precision of 0.002 arc seconds. Calculate, in metres, the maximum distance measurable by Hipparcos.

Wien’s displacement law for black body radiation is given by λmaxT = constant. Is λmax wavelength at which maximum emission occurs

Given the suns output power is 4.0x10^26. Find the average temperature of the sun

A: absolute magnitude: 1.40 apparent magnitude: –1.4 diameter / 10^3 km: 2400 temperature/K: 10 000 B: absolute magnitude: 11.2 apparent magnitude: 8.4 diameter / 10^3 km: 12 temperature/K 25 000 Calculate the distance to Star B in Pc

Which star will be the hottest and why?

In which two spectral classes are the presence of Hydrogen Balmer absorption lines prominent features?

Describe how Hydrogen absorption lines are produced in the spectrum of a star: Light from the star passes through the [blank_start]atmosphere[blank_end] of the star which contains [blank_start]hydrogen[blank_end] with electrons in [blank_start]n = 2[blank_end] state electrons in this state absorb certain energies and hence [blank_start]frequencies[blank_end] of light the light is re-emitted in all [blank_start]directions[blank_end], so that the [blank_start]intensity[blank_end] of these frequencies is [blank_start]reduced[blank_end] in any given direction, resulting in [blank_start]absorption lines[blank_end].

Explain what is meant by light year and parsec.