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Question 1 (In DBMS like Oracle) Which of the following allow null values ? A Unique Key or Primary Key ? Answer : Primary Key constraint does not allow null values to be inserted while it is legal in case of Unique key. Question 2 Considering an Oracle database as an example, can NULL values be used in arithmetic operations ? Explain your answer ? Answer : No, NULL value cannot be used in arithmetic operation. This is because a NULL just denotes an 'absence' of information rather than 'empty' or 'zero' value. Question 3 How you can delete a duplicate row from Unique key column? Answer : This necessity does not arise. First of all Unique key column will not allow duplicate rows to be inserted. Question 4 Tell any one advantage of using stored procedures in applications? Answer : Stored Procedures abstract complex SQL queries from application code. For example, a task involving multiple lines of complex SQL queries can be simpli...

Question 1 What is the sum of the irrational roots of the equation (x-1)(x-3)(x-5)(x-7)=9 ? a)10 b)8 c)6 d)4 Answer : b)8 Solution: Given that (x - 1) (x - 3) (x - 5) (x - 7) = 9 Let x - 4 = p Then the given eqn becomes (p + 3) (p + 1) (p - 1) (p - 3) = 9 (p 2 - 1) (p 2 - 9) = 9 p 4 - 10p 2 + 9 = 9 p 2 (p 2 - 10) = 0 p 2 =0 or p 2 -10 =0 p = 0 or p = sqrt(10) or p = - sqrt(10) then x - 4 = 0, x - 4 = sqrt(10) or x - 4 = - sqrt(10) Now the roots of the given eqn are 4,4 + sqrt(10) and 4 - sqrt(10) The irrational roots are 4+sqrt(10) and 4 - sqrt(10) The sum of the irrational roots = 4 + sqrt(10) + 4 - sqrt(10) = 8. Hence the answer is 8. Question 2 The product of the distinct roots of the equation (3x)(3x+2)(3x-4)(3x-6)= 64 is: a)-32/27 b)-61/5 c)63/16 d)69/12 Answer : a)-32/27 Solution: Given that (3x)(3x+2)(3x-4)(3x-6)= 64 Let 3x - 2 = p Then the given eqn becomes (p + 2) (p + 4) (p - 2) (p - 4) = 64 (p 2 - 4) (p 2 - 16...

The written test composed of 3 sections. 1)Verbal Ability 2)Aptitude & Analytical Reasoning 3)Technical In the Verbal Ability qn. Based on fill in the blanks,antonyms,synonyms,idioms etc. were there.You also hav to correct the sentences choosing the answer from the options given.All in all the qn. was a standard one & needed time to do.It consisted of 20 qn. The Analytical Reasoning qn. were good & consisted of problems on car parking,probability,profit & loss,time & work,train timing problem,sitting arrangement & time & distance.Practise of R.S Agarwal is sufficient for this. The technical qn. were short & consisted of qn. based on logic gates,finding outputs,data structure,prefix, for loop,unix & what is used in the CRT monitor.A firm & basic knowledge can easily help in the technical section. Now after the break through in written the technical PI took place.In this qn. based on stack,recursion,program on recursion were asked from m...

Interview questions based on important concepts in computer network. Question 1 Can you guess why IPv6 (Internet Protocol version 6) addresses came into existence while still IPv4 is being used by many machines? Answer : The only reason could be the enormous growth in the number of machines using v4 addresses. This forces concerned agencies to raise the address pool by some means. One of such ways was the introduction of IPv6 so that more machines can be accommodated. Question 2 Consider two network layer devices, one operating at network layer and the other operating at data link layer. In very generic terms, which one is more intelligent ? Explain with example. Answer : Generally a device that operates at a higher layer in OSI model is intelligent. For example, there are switches that operate at data link layer and some others that operate at network layer. Simply due to the additional capabilities of the switches that operate in network layer they can be ...

Three sample questions based on bank related transactions. Question 1 Ritika is a student of a famous Engineering College in Ongole. She wanted to buy a mobile phone but she is not inclined to disturb her father who is a farmer. A local Bank was ready to extend a loan for purchase of mobiles by students on simple interest. She chose a phone that costs 1500. The interest rate on the loan is 12%. If the loan is to be paid back in weekly installments over 2 years, calculate: 1. The amount of interest paid over two years 2. The total amount to be paid back 3. The weekly payment amount (a) 300, 1800, 18 (b) 320, 1820, 22 (c) 350, 1850, 25 (d) 360,1860, 17.88 Answer : d) 360,1860, 17.88 Solution: Principal, P=1500 Number of Years, N= 2 years Rate of interest per annum, R=12% Simple Interest,SI= P X N X R / 100 =1500X2X12 / 100=360. Amount of interest to be paid back in 2 years is 360. Total amount to be paid back P + SI= 1500 + 360=1860. This is to be pai...