Periyar University 2008 B.E Electronics

43) A moves three kms east from his starting point. He then travels five kms north. From that point he moves eight kms to the east. How far is A from his starting point?

Ans: 13 kms





44) A plane moves from 9°N40°E to 9°N40°W. If the plane begins at 10 am and takes eight hours to reach the destination, obtain the local arrival time.







45) In Madras , temperature at noon varies according to -t^2/2 + 8t + 3, where t is elapsed time. obtain how much temperature more or less in 4pm to 9pm. (May be we can solve it by Definite Integration. Check any way}

Ans: at nine pm 7.5 more or 385.8 (DB)





46) For Temperature a function is provided according to time: ((t**2)/6) + 4t +12 what is the temperature rise or fall ranging from 4.AM TO nine AM

Sol: In formula 1st put t=9,

We will get 34.5........................... (1)

Now put t=4,

We will get 27.............................. (2)

So Ans=34.5-27

=7.5







47) For Temperature a function is provided according to time: ((t**2)/6) + 4t +12 what is the temperature rise or fall ranging from five PM to eight PM




48) Low temperature at the night in a city is 1/3 more than 1/2 high as higher temperature in a day. Sum of the low tem. And highest temp is 100 degrees. Then what is the low temp?

Sol: Let highest temp be x

So low temp=1/3 of x of 1/2 of x plus x/2 i.e. x/6+x/2

Total temp=x+x/6+x/2=100

Therefore, x=60

least temp is 40

Ans :( 40 deg.)





49) A person had to multiply 2 numbers. Instead of multiplying by 35, he multiplied by 53and the product went up by 540. What was the raised product?

a) 780

b) 1040

c) 1590

d) 1720


Sol: x*53-x*35=540=> x=30 therefore, 53*30=1590


Ans: 1590





50) How many positive integer solutions does the formula 2x+3y = 100 have?

a) 50

b) 33

c) 16


d) 35


Sol: provided 2x+3y=100, take l.c.m of 'x' coeff and 'y' coeff i.e. l.c.m of 2,3 ==6then divide 100 with six , which turns out 16 hence ans is 16short cut formula--- constant / (l.cm of x coeff and y coeff)

Earning:   Approval pending.