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प्र: What kind of crystalline solid is graphite? 2163 0

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    Metallic
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    Ionic
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    Molecular
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    Covalent- network
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उत्तर : 4. "Covalent- network"
व्याख्या :

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.

प्र: The payment per hour for a daily-wages employee is increased by 33.33 and the working time is reduced by 33.33%. What is the percentage change in the employee's income ? 2162 0

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    11.11% decrease
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    21.11% increase
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    11.11% increase
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    21.11% decrease
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उत्तर : 1. "11.11% decrease"
व्याख्या :

Answer: A) 11.11% decrease Explanation: If earlier he is getting Rs. 1  per hr and working for 1 hr, income = Rs. 1Now he is getting Rs 1.3333 per hr and working for 0.66667 hrs Then income for 0.66667 hrs = Rs. 0.8889. If payment per hr is increased by 33.33 %  and working hours dereased by 33.33%, then 11.11 % decrease in income.

प्र: A Bus travels first half distance between two places with a speed of 40 kmph and the rest half distance with a speed of 60 kmph. The average speed of the Bus is ? 2162 0

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    48 kmph
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    50 kmph
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    46 kmph
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    42 kmph
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उत्तर : 1. "48 kmph"
व्याख्या :

Answer: A) 48 kmph Explanation: we know that speed = distance traveled/time takenlet the total distance traveled by the car is 2x km.then time taken by it to cover first half is x/60 hour.and for second half is x/40 hour.Then average speed= total distance travelled / total time taken.   i.e. 2xx60+x40   => 2x5x120   = 48 kmph.

प्र: The sum of one-half, one-third and one-fourth of a number exceeds the number by 22. The number is 2161 0

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    264
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    284
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    215
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    302
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उत्तर : 1. "264"
व्याख्या :

Answer: A) 264 Explanation: Let the number be 'x'. Then, from given data x/2 + x/3 + x/4 = x+2213x/12 = x+22x = 264

प्र: How many 4-letter words with or without meaning, can be formed out of the letters of the word, 'LOGARITHMS', if repetition of letters is not allowed ? 2161 0

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    5040
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    2525
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    2052
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    4521
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उत्तर : 1. "5040"
व्याख्या :

Answer: A) 5040 Explanation: The Word LOGARITHMS  contains 10 letters. To find how many 4 letter words we can form from that = P410 =10x9x8x7 = 5040.

प्र: 18 tens 20 ones = 2158 0

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    1820
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    180
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    200
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    160
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उत्तर : 3. "200"
व्याख्या :

Answer: C) 200 Explanation: 18 tens 20 ones, the given stateent can be split into 18 tens = 18 x 10 = 180 20 ones = 20 x 1 = 20   Then add both => 180 + 20 = 200   Hence, 18 tens 20 ones = 200.

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उत्तर : 1. "cough fight sough acts cats idea more"
व्याख्या :

Answer: A) cough fight sough acts cats idea more Explanation: Carefully obsrving the given arrangement, we find the following pattern:We observe that,first all the words with the highest number of letters are arranged in the alphabetical order, followed by the words with the second highest number of letters and so on.However, the position of only one word is altered at each step.Input: more fight cats cough sough acts ideaStep1: cough more fight cats sough acts ideaStep2: cough fight more cats sough acts ideaStep3: cough fight sough more cats acts ideaStep4: cough fight sough acts more cats ideaStep5: cough fight sough acts cats more ideaStep6: cough fight sough acts cats idea more   Hence, the answer is A

प्र: What Room can Nobody Enter? 2157 0

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    War room
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    Spare room
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    Escape room
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    Mushroom
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उत्तर : 4. "Mushroom"
व्याख्या :

Answer: D) Mushroom Explanation: The Room can Nobody Enter is a Mushroom.

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