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#### A certain loan amounts, under compound interest, compounded annually earns an interest of Rs.1980 in the second year and Rs.2178 in the third year. How much interest did it earn in the first year?Option: 1 Rs.1600Option: 2 Rs.1800Option: 3  Rs.1900Option: 4 None of these

xyz pqr abc year tt

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#### The distance between two stations A and B is 440 km. A train starts at 4 p.m. from A and move towards B at an average speed of 40 km/hr. Another train starts B at 5 p.m. and moves towards A at an average speed of 60 km/hr. How far from A will the two trains meet and at what time?Option: 1 200,8 p.m.Option: 2 300,9 p.m.Option: 3 200,9 p.m.Option: 4 300,8 p.m.

The sum of the distances covered by both trains should be equal to the total distance between the stations A and B: 40t+60(t−1)=44040t + 60(t - 1) = 44040t+60(t−1)=440

40t+60t−60=440
100t−60=440
100t=500
t=5

So, the trains will meet 5 hours after Train A starts from A.

Train A starts at 4 p.m. so 5 hours from 4 p.m. is 4 p.m. + 5 hours = 9 p.m.

The two trains will meet 200 km from A at 9 p.m.

Option 3: 200, 9 p.m.

#### PQ is a tunnel. A dog sits at the distance of 5/ 11 of PQ from P. The train whistle coming from any end of the tunnel would make the dog run. If a train approaches P and dog runs towards P the train would hit the dog at P. If the dog runs towards Q instead, it would hit the dog at Q. Find ratio of speed of train and dog?Option: 1 5:2Option: 2 16:5Option: 3 11:1Option: 4 34:3

Option 3 - 11:1

########            P____5_____¶______6_____Q

"¶" is the dog located inside the tunnel PQ and #####... is a train approaching to it.

Case 1 - Dog decides to reach point P

Distance covered by Dog - 5 parts and train reaches at P

Case 2 - Dog decides to run towards point Q

At the time train reaches to point P, the dog covers 5 parts in direction of Q. Now the left out part covered by dog will be 1 part towards Q .

At the time dog covers 1 part and reaches Q, train covers whole 11 parts of tunnel and reaches from P to Q.

So, 11 part of train is eual to the 1 part covered by the dog to reach Q.

Ratio of their speeds - Train:Dog = 11:1

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#### The following reaction occurs in the Blast Furnace where iron ore is reduced to iron metal : Fe2O3(s)+3 CO(g) 2 Fe(l)+3 CO2(g) Using the Le Chatelier’s principle, predict which one of the following will not disturb the equilibrium ? Option: 1  Removal of CO Option: 2  Removal of CO2 Option: 3 Addition of CO2 Option: 4 Addition of Fe2O3

According to Le Chatelier's principle change in concentration by changing the amount of reactant or product affect the equilibrium. However, the addition of solid reactant won't affect the concentration.

Therefore, addition of solid Fe2O???3 will not disturb the equilibrium.

#### The ore that contains the metal in the form of fluoride is : Option: 1 Cryolite Option: 2 Malachite Option: 3 Magnetite Option: 4 Sphalerite

The formula of the ores -

$1)$ $Cryolite-Na_{3}AlF_{6}$

[Contains the metal in the form of fluoride]

$2)$ $Malachite-\; CuCO_{3}.Cu\left ( OH \right )_{2}$

$3)$ $Magnetite-Fe_{3}O_{4}$

$4)$ $Sphalerite-ZnS$

So, option 1 is correct.

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#### The purest form of commercial iron is: Option: 1 wrought iron Option: 2 pig iron Option: 3 scrap iron and pig iron Option: 4 cast iron

The purest form of iron is wrought iron.

Therefore, Option(1) is correct.

#### Among the reactions (a)  - (d), the reaction(s) that does / do not occur in the blast furnace during the extraction of iron is / are :(a)  $CaO+SiO_{2}\rightarrow CaSiO_{3}$ (b)  $3Fe_{2}O_{3}+CO\rightarrow 2Fe_{3}O_{4}+CO_{2}$ (c)  $FeO+SiO_{2}\rightarrow FeSiO_{3}$ (d)  $FeO\rightarrow Fe+\frac{1}{2}O_{2}$ Option: 1 (C) and (D) Option:2  (A) Option: 3 (A) and (D) Option: 4 (D)

The following reactions do not occur in the blast furnace:

C) $\mathrm{FeO}+\mathrm{SiO}_{2} \rightarrow \mathrm{FeSiO}_{3}$

D) $\mathrm{FeO} \rightarrow \mathrm{Fe}+\frac{1}{2} \mathrm{O}_{2}$

Therefore, Option(1) is correct.

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#### The refining method used when the metal and the impurities have low and high melting temperatures, respectively is: Option: 1 vapour phase refining Option: 2 distillation Option: 3 liquation Option: 4 zone refining

As we have learnt,

Liquation -

In this method, a low melting metal like a tin can be made to flow on a sloping surface. In this way, it is separated from higher melting impurities.

-

Liquation, a technique for separating constituents of ore, a metal or an alloy by partial melting. When the material is heated to a temperature where one of the constituents melts and the other remains solid, the liquid constituent can be drained off.

Therefore, Option(3) is correct.

#### The element that can be refind by distillation is :Option: 1 nickelOption: 2 zincOption: 3 tin  Option: 4 gallium

Impure zinc is refined by the distillation method.

Therefore, the correct option is (2).