Astronomy

1.	Q1
	Newly formed neutron stars have weak magnetic fields which strengthen over time, due to the conservation of angular momentum. Student Response Value Correct Answer False 100% False Score: 5/5
2.	Q2
	The density of a neutron star is comparable to the density of an atomic nucleus. Student Response Value Correct Answer True 100% True Score: 5/5
3.	Q3
	All neutron stars must begin as millisecond pulsars just after their supernova creation. Student Response Value Correct Answer False 100% False Score: 5/5
4.	Q4
	X-ray bursters are similar to novae, except the collapsed star is a neutron star, not a white dwarf. Student Response Value Correct Answer True 100% True Score: 5/5
5.	Q5
	Gamma-ray bursts seem to come primarily from neutron star binaries in the plane of our own Milky Way Galaxy. Student Response Value Correct Answer False 100% False Score: 5/5
6.	Q6
	The escape speed for a black hole's event horizon is the speed of light. Student Response Value Correct Answer True 100% True Score: 5/5
7.	Q7
	The Schwarzschild radius of a black hole is about 3 km per solar mass; it is amazingly linear over a wide range of masses. Student Response Value Correct Answer True 100% True Score: 5/5
8.	Q8
	Special relativity says that c, the speed of light, is the maximum velocity for both matter and energy in our universe. Student Response Value Correct Answer True 100% True Score: 5/5
9.	Q9
	Two important properties of young neutron stars are   Student Response Value Correct Answer Feedback 1. extremely slow rotation and a strong magnetic field.     2. extremely rapid rotation and a weak magnetic field.      3. extremely rapid rotation and a strong magnetic field. 100%      4. no rotation and a weak magnetic field.     5. no rotation and no magnetic field.     Score: 5/5
10.	Q10
	Pulsars   Student Response Value Correct Answer Feedback  1. spin very rapidly when they're young. 100%      2. are the cause of gamma-ray bursts.     3. spin very slowly when they're young, and gradually spin faster as they age.     4. generally form from 25 solar mass stars.     5. emit radio in all directions.     Score: 5/5
11.	Q11
	The vast majority of pulsars are known only from their pulses in:   Student Response Value Correct Answer Feedback 1. gamma rays     2. visible light     3. microwaves     4. x-rays      5. radio waves 100%      Score: 5/5
12.	Q12
	What makes the Crab pulsar somewhat unusual among pulsars in general?   Student Response Value Correct Answer Feedback 1. It is the most intense source of X-rays in the sky.     2. It is the fastest pulsar known.     3. It is the oldest pulsar observed     4. Its period is not regular like other pulsars.      5. It is rather bright at visible wavelengths. 100%      Score: 5/5
13.	Q13
	The supernova of 1054 AD produced:   Student Response Value Correct Answer Feedback  1. a remnant still visible to the naked eye, the Crab Nebula, M-1. 0%     2. a pulsar with a period of 33 milliseconds, visible optically.      3. the closest known neutron star to our Sun.     4. the most famous black hole.     5. no remaining visible trace, as it was a type I supernova.     Score: 0/5
14.	Q14
	To which of these phenomena are X-ray busters most similar?   Student Response Value Correct Answer Feedback  1. novae 100%      2. planetary nebulae     3. type I supernovae     4. type II supernovae     5. hypernovae     Score: 5/5
15.	Q15
	Which of the following can actually escape from inside a black hole's event horizon?   Student Response Value Correct Answer Feedback 1. neutrinos     2. electrons     3. very high energy gamma-rays     4. gravitons      5. none of the above 100%      Score: 5/5
16.	Q16
	A hypernova creates   Student Response Value Correct Answer Feedback 1. a black hole      2. a pulsar     3. a neutron star      4. short-duration gamma ray bursters 0%     5. Both A and C are correct     Score: 0/5
17.	Q17
	What explanation does general relativity provide for gravity?   Student Response Value Correct Answer Feedback  1. Gravity is the result of curved spacetime. 100%      2. Gravity is directly proportional to the mass of the attracting body.     3. Gravity is inversely proportion to the radius of the body.     4. Gravity is the opposite of the electromagnetic force     5. Gravity can affect only massive particles, not massless photons.     Score: 5/5
18.	Q18
	As a spaceship's velocity gets closer to the speed of light   Student Response Value Correct Answer Feedback 1. its length will increase and its clock will run more slowly.     2. its length will decrease and its clock will run faster.     3. its length will increase and its clock will run faster.      4. its length will decrease and its clock will run more slowly. 100%      5. None of these will happen.     Score: 5/5
19.	Q19
	If light from a distant star passes close to a massive body, the light beam will   Student Response Value Correct Answer Feedback  1. bend towards the star due to gravity. 100%      2. continue moving in a straight line.     3. change color to a shorter wavelength.     4. slow down.     5. accelerate due to gravity.     Score: 5/5
20.	Q20
	What is Cygnus X-1?   Student Response Value Correct Answer Feedback 1. the brightest star in the constellation Cygnus      2. the leading candidate for an observable black hole binary system 100%      3. the strongest X-ray eclipsing binary system in the sky     4. a millisecond pulsar with three Earth-like planets around it     5. the first gamma-ray burster to be spotted in other wavelengths as well     Score: 5/5