IIT JEE Practice Question and Answer
8Q: Which of the following is the strongest acid? 1339 05b5cc6b7e4d2b4197774d5ec
5b5cc6b7e4d2b4197774d5ec- 1ClCH2COOHfalse
- 2BrCH2COOHfalse
- 3FCH2COOHtrue
- 4ICH2COOHfalse
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 3. "FCH2COOH"
Explanation :
Answer: C) FCH2COOH Explanation: FCH2COOH is the strongest acid out of all .Since the electron withdrawing inductive effect (-I effect) of the halogens decreases in the order F>Cl> Br> I , therefore the acidic strength of the α- halo acids decreases in the same order. FCH2COOH > ClCH2COOH > BrCH2COOH > ICH2COOH.
Q: The average of marks in 3 subjects is 224. The first subject marks is twice the second and the second subject marks is twice the third. Find the second subject marks ? 1337 05b5cc6cce4d2b4197774e17c
5b5cc6cce4d2b4197774e17c- 1384false
- 296false
- 3192true
- 4206false
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 3. "192"
Explanation :
Answer: C) 192 Explanation: Let the third subject marks be 'x'=> Second subject marks = 2x=> Third subject marks = 4xGiven avg = 224x + 2x + 4x = 224 x 3=> 7x = 224 x 3=> x = 96Hence, Second subject marks = 2x = 2 x 96 = 192.
Q: Important component that helps in clotting of the blood is called ____. 1336 05b5cc6c5e4d2b4197774dd8c
5b5cc6c5e4d2b4197774dd8c- 1Haemoglobinfalse
- 2Plateletstrue
- 3Serumfalse
- 4Plasmafalse
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 2. "Platelets"
Explanation :
Answer: B) Platelets Explanation: Blood Platelets are the components of the blood that are helpful in clotting of the blood.
Q: 'Minamata' disease was caused by ? 1336 05b5cc723e4d2b4197774f6b4
5b5cc723e4d2b4197774f6b4- 1Leadfalse
- 2Mercurytrue
- 3Cadmiumfalse
- 4Zincfalse
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 2. "Mercury"
Explanation :
Answer: B) Mercury Explanation:
Q: What least number must be substracted from 627349 so that the remaining number is divisible by 15 ? 1336 05b5cc754e4d2b4197774fb9a
5b5cc754e4d2b4197774fb9a- 11false
- 22false
- 33false
- 44true
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 4. "4"
Explanation :
Answer: D) 4 Explanation: On dividing 627349 by 15, we get remainder = 4.Therefore, the obtained remainder is the least number to be subtracted from the given number so that the the mnumber is divisible by 15.Here 4 is the least number to be subtracted from 627349 so that it is divisible by 15.
Q: Gases in the atmosphere and their percentages? 1336 05b5cc619e4d2b4197774b744
5b5cc619e4d2b4197774b744- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer :
Explanation :
The air around us is a mixture of gases, mainly nitrogen and oxygen, but containing much smaller amounts of water and other gases. Earth's atmosphere is composed of many gases. Their percentages by volume is given by:: 78% Nitrogen, 21% Oxygen, 0.9% Argon, and 0.03% Carbon dioxide And very small percentages of other elements.
Q: What is the most commonly spoken language in the world? 1336 05b5cc69ae4d2b4197774c773
5b5cc69ae4d2b4197774c773- 1Mandarin Chinesetrue
- 2Englishfalse
- 3Spanishfalse
- 4Hindifalse
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 1. "Mandarin Chinese"
Explanation :
Answer: A) Mandarin Chinese Explanation:
Q: There are 6561 balls are there out of them 1 is heavy. Find the minimum number of times the balls have to be weighted for finding out the heavy ball ? 1335 05b5cc70ee4d2b4197774f351
5b5cc70ee4d2b4197774f351- 12414false
- 2204false
- 387false
- 48true
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 4. "8"
Explanation :
Answer: D) 8 Explanation: Suppose there are 9 balls Let us give name to each ball B1 B2 B3 B4 B5 B6 B7 B8 B9 Now we will divide all the balls into 3 groups. Group1 - B1 B2 B3 Group2 - B4 B5 B6 Group3 - B7 B8 B9 Step1 - Now weigh any two groups. Let's assume we choose Group1 on left side of the scale and Group2 on the right side. So now when we weigh these two groups we can get 3 outcomes. Weighing scale tilts on left - Group1 has a heavy ball.Weighing scale tilts on right - Group2 has a heavy ball.Weighing scale remains balanced - Group3 has a heavy ball.Lets assume we got the outcome as 3. i.e Group 3 has a heavy ball. Step2 - Now weigh any two balls from Group3. Lets assume we keep B7 on left side of the scale and B8 on right side. So now when we weigh these two balls we can get 3 outcomes. Weighing scale tilts on left - B7 is the heavy ball.Weighing scale tilts on right - B8 is the heavy ball.Weighing scale remains balanced - B9 is the heavy ball.The conclusion we get from this Problem is that each time weigh. We element 2/3 of the balls. As we came to conclusion that Group3 has the heavy ball from Step1, we remove 6 balls from the equation i.e (2/3) of 9. Simillarly we do the ame thing for the Step2. Now going with this conclusion. We have 6561 balls. Step - 1 Divided into 3 groups Group1 - 2187Balls Group2 - 2187Balls Group3 - 2187Balls Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball. Step - 2 Divided into 3 groups Group1 - 729Balls Group2 - 729Balls Group3 - 729Balls Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball. Step - 3 Divided into 3 groups Group1 - 243Balls Group2 - 243Balls Group3 - 243Balls Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball. Step - 4 Divided into 3 groups Group1 - 81Balls Group2 - 81Balls Group3 - 81Balls Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball. Step - 5 Divided into 3 groups Group1 - 27Balls Group2 - 27Balls Group3 - 27Balls Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball. Step - 6 Divided into 3 groups Group1 - 9Balls Group2 - 9Balls Group3 - 9Balls Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball. Step - 7 Divided into 3 groups Group1 - 3Balls Group2 - 3Balls Group3 - 3Balls Taking the similar steps as we did in the above example, we come to the conclusion that Group1 has the heavy ball. Step - 8 So now when we weigh 2 balls out of 3 we can get 3 outcomes. Weighing scale tilts on left - left side placed is the heavy ball.Weighing scale tilts on right - right side placed is the heavy ball.Weighing scale remains balanced - remaining ball is the heavy ball.So the general answer to this question is, it is always multiple of 3 steps. For 9 balls 32= 9. therefore 2 steps For 6561 balls 38 = 6561 therefore 8 steps

