Question Discussion & Solution

The correct answer is Copper.

Key Points

• Conductor of electricity
  • In physics and electrical engineering, a conductor is an object or type of material that allows the flow of charge in one or more directions.
  • Materials made of metal are common electrical conductors. 
  • Copper is considered to be a conductor because it conducts the electron current or flow of electrons fairly easily. Most metals are considered to be good conductors of electrical current. Copper is just one of the more popular materials that are used for conductors. Hence, Option 4 is correct.
  • If you have to define the meaning of electrical conductors in the simplest way, they are materials that allow electricity to flow through them easily.
  • If we compare two types of material and the first one allows better flow of electricity through it, then that material is said to be a good conductor of electricity.
  • An electrical conductor allows the electric charges to easily flow through them. The property of conductors to conduct electricity is called conductivity.
  • Such materials offer less opposition or resistance to the flow of charges.
  • Conducting materials allow easy charge transfer because of the free movement of electrons through them.

Additional Information

• • Some examples of conductors of electricity are
    • Copper
    • Aluminum
    • Silver
    • Gold
    • Graphite
    • Platinum
    • Water
    • People

The correct answer is Potato.

Modifications of Root

1. For storage of food
   • Roots are modified in some plants for storing reserve food materials.
   • These modified roots usually are swollen and assume different forms such as spindle-shaped, e.g., radish; top-shaped, e.g., beet, turnip; cone-like, e.g., carrot; indefinite shape, e.g., sweet potatoes.
   • Dahlia, Asparagus, Portulaca are some other examples of plants with modified roots for food storage.
2. Nodulated roots
   • The roots of pea and other leguminous plants have numerous swollen nodules on fine branches of roots.
   • These nodules are formed due to the symbiotic association of Rhizobium (bacterium) that live inside the root cortical cells of the roots.
   • They fix nitrogen and an active nodule is pink in colour.
3. For mechanical support
   • Roots are modified to provide mechanical support as seen in a banyan tree which has roots growing vertically/obliquely downwards (prop roots); sugarcane/maize in which roots arise from the nodes in the cluster at the base of the stem (stilt roots) and betel/black pepper in which nodes and internodes bear roots which help in climbing.
4. For gaseous exchange
   • Pneumatophores or breathing roots are found in plants growing in mangroves or swamps with saline water for exchange of gases.
   • They are erect peg-like structures with numerous pores through which air circulates e.g., Rhizophora mangle.

• Modifications of Stem

1. For storage of food
   • Stems get modified into underground structures for storage of food as seen in potato (tuber), ginger (rhizome), garlic (bulb), yam (corm).
   • Presence of an eye (node) in potato, distinct nodes with internodes and scaly leaves in ginger/yam, a cluster of roots at the base of the reduced stem in garlic/ onion, all indicate that these underground plant parts are modified stem.
2. For vegetative propagation
   • Plants besides reproducing sexually also propagate through vegetative parts.
   • For this purpose, stems may be modified into a runner (Cyanodon dactylon, Oxalis). Runners are slender prostrate branches arising from axillary buds;
   • stolon (e.g., mint, strawberry) which is a slender lateral branch arising from the base of the stem grows upward and then down to develop new daughter plants;
   • offset having a single long horizontal internode growing up to some distance and producing a tuft of leaves above and a cluster of roots below at the apex (Eichornia, Pistia) and
   • sucker, which arises from the underground part of the stem, grow obliquely and gives rise to a new shoot. (Chrysanthemum, Banana, Pineapple).
3. For protection
   • Some modified stem provides protection as thorns which are hard, pointed structures each representing a branch that arises from the axil of a leaf.
   • Thorns are found in plants like Duranta, Pomegranate, Acacia, Ber, Prosopis, Bougainvillea, Citrus, etc.
4. For support
   • Tendrils are modifications of the stem to provide support to plants, e.g., Vitis, passionflower, Bignonia etc.
5. For photosynthesis
   • Stems are also modified into Phylloclade, to facilitate photosynthesis.
   • Phylloclades are flattened/cylindrical stem or branches of unlimited growth (Cactus).

The correct answer is DBMS.

Key Points

• DBMS is NOT antivirus software.
• A database is a collection of related data that depicts a real-world situation. A database system is made to be developed and filled with information for a certain activity.
• A database management system (DBMS) is software that stores and retrieves data for users while taking proper security precautions. It is made up of a collection of applications that manipulate the database.
• The DBMS accepts an application's request for data and informs the operating system to give the requested data.
• A database management system (DBMS) aids users and other third-party applications in storing and retrieving data in huge systems.
• Users can design their own databases using a database management system (DBMS).
• The term "DBMS" refers to the database user as well as other application applications. It serves as a link between the data and the software program.

• McAfee Corp. is a San Jose, California-based global computer security software corporation.
• Avast Antivirus is a cross-platform internet security suite created by Avast for Microsoft Windows, macOS, Android, and iOS.
• Avira Operations GmbH & Co. KG is a German multinational computer security software firm best known for its Avira Free Security antivirus software. 

Rohit started walking towards the west.

He walked for 300 m and turned to his right from the post office.

From there, he walked for 200 m.

He then turned to the left and walked a few steps.

Rohit is now standing in front of West direction.

Hence, "West" is the correct answer.

The correct answer is 740 meters.

• The approximate height of Dhosi hill above sea level is 740 meters.

Key Points

• Dhosi hill
  • ​Dhosi Hill is an extinct volcano.
  • It is standing alone at the northwest end of the Aravalli mountain range, of which it is a part, with height varying from about 345 to 470 meters from the surrounding land.
  • It is 740 meters from sea level. 
  • Dhosi Hill is located on the borders of Haryana and Rajasthan.

Additional Information

Top 3 Major mountain peaks of the Aravali Ranges of Rajasthan: