Answer: D) Covalent- network Explanation: Graphite is a covalent-network type of crystalline solid.   There are two main categories of solids. 1. Crystalline solids and 2. Amorphous solids. Crystalline solids are those in which the atoms, ions, or molecules that make up the solid exist in a regular, well-defined arrangement. There are four types of crystalline solids : Ionic solids :— Made up of positive and negative ions and held together by electrostatic attractions. They’re characterized by very high melting points and brittleness and are poor conductors in the solid state. An example of an ionic solid is table salt, NaCl. Molecular solids :— Made up of atoms or molecules held together by London dispersion forces, dipole-dipole forces, or hydrogen bonds. Characterized by low melting points and flexibility and are poor conductors. An example of a molecular solid is sucrose. Covalent-network (also called atomic) solids :— Made up of atoms connected by covalent bonds; the intermolecular forces are covalent bonds as well. Characterized as being very hard with very high melting points and being poor conductors. Examples of this type of solid are diamond and graphite, and the fullerenes. As you can see below, graphite has only 2-D hexagonal structure and therefore is not hard like diamond. The sheets of graphite are held together by only weak London forces! Metallic solids :— Made up of metal atoms that are held together by metallic bonds. Characterized by high melting points, can range from soft and malleable to very hard, and are good conductors of electricity.

Answer: D) Dry Land Farming Explanation:

Answer: C) Rs. 9000 Explanation: Let Rs. K invested in each scheme Two years C.I on 20% = 20 + 20 + 20x20/100 = 44% Two years C.I on 15% = 15 + 15 + 15x15/100 = 32.25% Now, (P x 44/100) - (P x 32.25/100) = 528.75 => 11.75 P = 52875 => P = Rs. 4500   Hence, total invested money = P + P = 4500 + 4500 = Rs. 9000.

Answer: B) 144 km Explanation: Given a jeep travels a certain distance taking 6 hrs in forward journeyDuring the return journey, it takes 4 hrs with an increased speed 12 km/hrLet 'x' be the distance.Now, speed is given by distance/time.Here the difference between both speeds = 12  x4 - x6 = 12  3x - 2x12 = 12   => x = 144 km   Therefore, the distance travelled by the jeep in forward or return journey is x = 144 km.

Answer: B) 6th century BCE Explanation: Zoroastrianism is one of the world's oldest extant religions. It is the ancient pre-Islamic religion of Iran that survives there in isolated areas and, more prosperously, in India, where the descendants of Zoroastrian Iranian (Persian) immigrants are known as Parsis, or Parsees.   The Iranian prophet and religious reformer Zarathustra flourished before the 6th century BCE more widely known outside Iran as Zoroaster is traditionally regarded as the founder of the religion.   Zoroastrianism contains both monotheistic and dualistic features. It likely influenced the other major Western religions—Judaism, Christianity, and Islam.

Answer: A) Angle of declination Explanation:

Answer: D) All the above Explanation: The central nervous system CNS is responsible for integrating sensory information and responding accordingly. It consists of two main components::  1. The brain  2. The spinal cord The brain is the center of our thoughts, the interpreter of our external environment, and the origin of control over body movement. The brain can be divided into four main lobes: temporal, parietal, occipital and frontal.   The spinal cord serves as a conduit for signals between the brain and the rest of the body.

Answer: D) Rs.50,589.47 Explanation: Let the total earnings be Rs.x  Then 412% of x + 14% of (x-12000) =2400  ⇒92×x100+14×x-12000100=2400 =>  x=50,589.47