The following 20 Multiple Choice Questions (MCQ) are based on
Chapter 11: Keeping Time with the Skies from the NCERT Class 8
Science textbook Curiosity. Each question has four options - select the
best answer and click to check.
Instructions: Read each question carefully. Choose the most
appropriate option from (a), (b), (c), or (d). Click
Show Answer to reveal the correct answer with explanation.
Multiple Choice Questions
1The Moon shines because it:
(a) Reflects sunlight
(b) Produces its own visible light
(c) Burns like the Sun
(d) Is made of mirrors
(a) is correct
Sunlight illuminates half the Moon, and some reflected light reaches Earth.
2The changing apparent shapes of the Moon are called:
(a) Seasons
(b) Solstices
(c) Orbits
(d) Phases
(d) is correct
Phases result from seeing different portions of the Moon's sunlit half.
3Why is the entire illuminated half of the Moon not visible every night?
(a) The Moon changes shape physically
(b) Clouds always hide the same part
(c) The relative positions of Sun, Earth and Moon change
(d) Earth's shadow covers it every night
(c) is correct
The viewing angle changes as the Moon revolves around Earth.
4A full Moon occurs when Earth is approximately:
(a) At the Moon's pole
(b) Between the Sun and Moon
(c) On the same side as the Moon from the Sun
(d) Inside the Moon
(b) is correct
The lunar hemisphere facing Earth is then almost fully sunlit.
5A new Moon occurs when the Moon is approximately:
(a) Between Earth and the Sun
(b) Opposite the Sun with Earth between
(c) At Earth's north pole
(d) Outside its orbit
(a) is correct
Its sunlit side faces mostly away from Earth.
6The interval from one full Moon to the next is about:
(a) 24 hours
(b) 7 days
(c) 365 days
(d) 29.5 days
(d) is correct
The synodic lunar month is approximately 29.5 days.
7When the visible bright portion is increasing, the Moon is:
(a) Eclipsed
(b) Stationary
(c) Waxing
(d) Waning
(c) is correct
Waxing phases progress from new Moon toward full Moon.
8When the visible bright portion is decreasing, the Moon is:
(a) Producing less light
(b) Waning
(c) Waxing
(d) At perihelion
(b) is correct
Waning phases progress from full Moon toward new Moon.
9A lunar eclipse differs from ordinary phases because an eclipse involves:
(a) Earth's shadow falling on the Moon
(b) The Moon changing shape
(c) A monthly disappearance caused by clouds
(d) The Sun switching off
(a) is correct
Phases are viewing geometry; a lunar eclipse requires close alignment with Earth's shadow.
10A lunar calendar is based mainly on:
(a) Earth's daily rotation only
(b) Wind seasons only
(c) Atomic clocks only
(d) Cycles of Moon phases
(d) is correct
Months follow the repeating lunar phase cycle.
11A solar calendar is based mainly on:
(a) Tides only
(b) Daily temperature
(c) Earth's revolution around the Sun
(d) Moon phases only
(c) is correct
Its year tracks the seasonal cycle associated with one orbit of Earth.
12A luni-solar calendar coordinates:
(a) Only sunrise times
(b) Lunar months with the solar year
(c) Only clock hours
(d) Only eclipses
(b) is correct
Adjustments such as an added month keep lunar dates aligned with seasons.
13Why may a luni-solar calendar add an extra month?
(a) To keep lunar months aligned with the solar year
(b) To shorten every year
(c) To stop Moon phases
(d) To create a new season
(a) is correct
Twelve lunar months are shorter than a solar year, so periodic correction is needed.
14The Indian National Calendar is based on the:
(a) Gregorian Era only
(b) Roman lunar cycle
(c) Martian year
(d) Saka Era
(d) is correct
India's national civil calendar uses the Saka Era alongside the Gregorian calendar for official purposes.
15The first month of the Indian National Calendar is:
(a) Paush
(b) Bhadra
(c) Chaitra
(d) Kartika
(c) is correct
The Saka year begins with Chaitra around the March equinox.
16Many festival dates vary in the Gregorian calendar because they are set using:
(a) Temperature records
(b) Lunar or luni-solar calendars
(c) Random selection
(d) Only weekdays
(b) is correct
Their traditional calendar date corresponds to a different Gregorian date from year to year.
17An artificial satellite remains in orbit because of:
(a) Its forward motion and Earth's gravity
(b) Absence of gravity
(c) Air supporting it
(d) Moonlight
(a) is correct
Gravity continually bends its path while inertia carries it forward.
18Which is an important use of Earth-observation satellites?
(a) Changing Moon phases
(b) Producing sunlight
(c) Stopping Earth's rotation
(d) Weather monitoring and mapping
(d) is correct
Satellite sensors repeatedly observe clouds, land, oceans and environmental changes.
19Communication satellites help by:
(a) Creating eclipses
(b) Measuring mass with a balance
(c) Relaying signals over large distances
(d) Making stars brighter
(c) is correct
They receive and retransmit radio, television, telephone and data signals.
20Why can the Moon sometimes be seen during daytime?
(a) Daytime has no sunlight
(b) It can be above the horizon and bright enough against the sky
(c) It produces light only by day
(d) It leaves its orbit
(b) is correct
Depending on its phase and position, reflected moonlight remains visible in daylight.
