Q1. How do electric batteries work?
(a) Batteries store and release electrical energy through magnetic fields.
(b) Batteries convert light energy into electrical energy.
(c) Batteries produce electricity by harnessing gravitational forces.
(d) Batteries generate electricity through chemical reactions.
Ans: (d)
Explanation: How do Electric batteries work?
- It works by converting stored chemical energy into electrical energy.
- Anode (Negatively Charged Electrode): Oxidation occurs, releasing electrons and creating ions.
- Cathode (Positively Charged Electrode): Reduction takes place, consuming electrons and accepting ions.
- Electron Flow: Electrons generated at the anode flow through an external circuit to the cathode, creating an electric current.
- Salt Bridge (electrolyte): A salt bridge connects the two half-cells, allowing ion exchange to maintain electrical neutrality.
Q2. What is the primary role of algae?
(a) Algae are terrestrial plants crucial for agricultural practices.
(b) Algae are microscopic animals found in marine environments.
(c) Algae are photosynthetic organisms that produce oxygen and serve as the base of aquatic food chains.
(d) Algae are fungi contributing to decomposition processes in soil.
Ans: (c)
Explanation:
- Algae, through the process of photosynthesis, produce oxygen and form the foundation of aquatic food chains. They are crucial contributors to the oxygen content in the Earth’s atmosphere and support various aquatic life forms.
Q3. Consider the following statements about Mount Etna:
- It is an active stratovolcano.
- It is located on the east coast of Sicily, Italy.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Ans: (c)
Explanation:
- Context: Mount Etna, Europe’s most active volcano, has been erupting for over a year, causing disruptions such as flight cancellations and vehicle bans due to ash accumulation.
About Mount Etna:
- It is an active stratovolcano on the east coast of Sicily, Italy, in the Metropolitan City of Catania and the highest Mediterranean island mountain. It is located above the convergent plate margin between the African Plate and the Eurasian Plate. Mount Etna, with a recorded history of volcanic activity dating back to 1500 B.C., has erupted over 200 times.
Q4. Consider the following pairs:
- Merapi – Indonesia
- Mauna Loa – Iceland
- Santa Maria – Guatemala
How many of the above given pairs are correctly matched?
(a) Only one
(b) Only two
(c) All three
(d) None
Ans: (b)
Explanation:
List of some of the most active volcanoes on Earth:
- Mount Etna – Italy – Highest Mediterranean Island Mountain, continuous eruptions
- Kilauea – Hawaii, USA – Long-term eruptions, ongoing since 1983
- Mauna Loa – Hawaii, USA – One of the largest shield volcanoes, last erupted in 1984
- Merapi – Indonesia – Frequent and highly explosive eruptions
- Eyjafjallajökull – Iceland – Disrupted air travel in 2010 with ash clouds
- Fagradalsfjall – Iceland – Ongoing eruptions attracted attention with recent activity
- Dukono – Indonesia – Long-term eruption since August 1933
- Santa Maria – Guatemala – Erupting since June 1922, one of the most active in Central America
- Yasur – Vanuatu – Erupting since about 1270 (± 110 years), ongoing
Q5. With reference to medieval India, which one of the following is the correct sequence in ascending order in terms of size?
(a) Paragana – Sarkar – Suba
(b) Sarkar – Paragana – Suba
(c) Suba – Sarkar – Paragana
(c) Suba – Sarkar – Paragana
Ans: (a)
Explanation:
- Each Sarkar, or district, in the entire Suba was supervised by a military official known as the chief Shiqdar. Parganas, or smaller divisions, were created for every Sarkar. In every Pargana, there were two Karkuns (clerks or writers), one Fotahdar (treasurer), one Amin or Munsif (civil judge), and one Shiqdar (military officer).
