EOY 10 Exam

Question 1

State whether the graphs in Figure 7 relate to a location in the Northern or Southern hemisphere.

Answer 1

Northern hemisphere

Question 2

State the reason for your answer to (i) above

Answer 2

longer days in summer, shorter days in winter/

Question 3

During two months of the year, local clocks were adjusted to allow for daylight‑saving time.
Figure 7 shows that these two months were:

Answer 3

B March and October

Question 4

State the feature of the graphs in Figure 7 that shows the effect of daylight‑saving time.

Answer 4

graph is not a smooth curve

Question 5

On 13th September she observes the Sun with a sundial. It shows a time of 15:01.
Estimate her Mean Solar Time (MST) at this time.

Answer 5

MST = 14:57
MST = AST – EOT
= 15:01 - 4

Question 6

Sarah then takes a further sundial reading 30 days later, on the 13th October.
She suggests that the Equation of Time for the 13th October would be +19 minutes.
Analyse the data in Figure 8 and comment on Sarah’s estimate for the Equation of Time on the 13th October

Answer 6

EOT would not be +19 minutes as maximum value for EOT is less than +19

Question 7

To measure Apparent Solar Time accurately, a sundial must be correctly aligned.
State two ways of ensuring this.

Answer 7

Gnomon / shadow caster must point north

Question 8

Calculate the ratio of the Moon’s current distance from the Earth to its distance when it formed.

Answer 8

11.2

Question 9

Explain what would happen to each of the following if the Moon orbited much closer to the Earth: the tides on the Earth

Answer 9

Greater range between high and low tide because gravitational force of the moon is greater

Question 10

Explain what would happen to each of the following if the Moon orbited much closer to the Earth: lunar phase cycle

Answer 10

short phase cycle because rotational period of moon around earth is shorter

Question 11

Explain what would happen to each of the following if the Moon orbited much closer to the Earth: the appearance of a total solar eclipse

Answer 11

Corona not visible because Moon appears bigger in the sky

Question 12

Calculate a value for the mean distance between the Earth and the Sun. Use the data from Figure 13 and the fact that both the Sun and the Moon have
the same apparent diameter

Answer 12

1.39 × 106

3470 (= 401

Question 13

Which label from Figure 14 marks the position of the first umbral contact?

Answer 13

B 2

Question 14

Which label from Figure 14 marks the position of the third umbral contact?

Answer 14

D 5

Question 15

State one feature of the Moon’s orbit which means that lunar and solar eclipses do not occur every month.

Answer 15

Moon’s orbit does not lie on the ecliptic

Question 16

State the time of local noon at the student’s location.

Answer 16

12:02

Question 17

Calculate the student’s longitude.

The Equation of Time on this date was 0 minutes

Answer 17

0.5 degrees west

Question 18

The ‘lunar distance’ method can be used to measure longitude. Which of the following measurements must be taken in this method?

Answer 18

The angular distance between the Moon and a

certain bright star

Question 19

State the reason why the dish in a radio telescope must be made from metal

Answer 19

Metal reflects radio waves

Question 20

Explain why the dish in this radio telescope needs to have a much larger diameter than the mirrors in the largest optical telescopes.

Answer 20

Radio waves have longer wavelength

Large aperture gives sufficient resolution.

Question 21

Where the inward pull of gravity is balanced by outward radiation pressure

Answer 21

Main Sequence star

Question 22

Where the inward pull of gravity is balanced by outward electron pressure

Answer 22

White Dwarf star

Question 23

Where the inward pull of gravity is balanced by outward neutron pressure.

Answer 23

Neutron star

Question 24

Describe what is meant by an emission nebula.

Answer 24

cloud of hydrogen gas and first stage in formation of a star

Question 25

Explain the difference between absolute magnitude and apparent magnitude.

Answer 25

Apparent magnitude is measured from the star’s
actual distance
Absolute magnitude is measured from the same
distance for all stars

Question 26

The star Sirius is actually 2.64pc from the Earth.

Calculate its apparent magnitude.

Answer 26

m = M - 5 + 5 log d
d = 0.42