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Q:

Hydrogen atom is excited from ground state to another state with principal quantum number equal to 4. Then the number of spectral lines in the emission spectra will be

A) 2	B) 6
C) 5	D) 3

Answer & Explanation Answer: B) 6

Explanation:

Number of spectral lines from a state n to ground state is

n(n-1)/2 = 6

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Filed Under: Physics
Exam Prep: AIEEE

Q:

A sum of money invested for a certain number of years at 8% p.a. simple interest grows to Rs.180. The same sum of money invested for the same number of years at 4% p.a. simple interest grows to Rs.120 only. For how many years was the sum invested?

A) 25years	B) 15years
C) 20years	D) 22years

Answer & Explanation Answer: A) 25years

Explanation:

From the information provided we know that,

Principal + 8% p.a. interest on principal for n years = 180 …….. (1)

Principal + 4% p.a. interest on principal for n years = 120 ……… (2)

Subtracting equation (2) from equation (1), we get

4% p.a. interest on principal for n years = Rs.60.

Now, we can substitute this value in equation (2),

i.e Principal + 60 = 120

= Principal = Rs.60.

We know that SI = , where p is the principal, n the number of years and r the rate percent of interest.

In equation (2), p = Rs.60, r = 4% p.a. and the simple interest = Rs.60.

Therefore, 60 =(60*n*4)/100

=> n = 100/4 = 25 years.

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Filed Under: Simple Interest
Exam Prep: Bank Exams
Job Role: Bank PO

Q:

What is the least number of squares tiles required to pave the floor of a room 15 m 17 cm long and 9 m 2 cm broad?

A) 814	B) 820
C) 840	D) 844

Answer & Explanation Answer: A) 814

Explanation:

Length of largest tile = H.C.F. of 1517 cm and 902 cm = 41 cm.

Area of each tile = (41 x 41) sq.cm

Required number of tiles = 1517 x (902/41) x 41 = 814

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Filed Under: Volume and Surface Area

Q:

Should jobs be linked with academic degrees and diplomas?

Arguments:

1. No. A very large number of persons with meagre academic qualifications will apply

2. No. Importance of higher education will be diminished

A) Only 1 is true	B) Only 2 is true
C) Either 1 or 2 is true	D) Neither 1 nor 2 is true

Answer & Explanation Answer: B) Only 2 is true

Explanation:

Delinking jobs with degrees will diminish the need for higher education as amny of them persue such education for jobs.So, only arg 2 is strong

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Filed Under: Statement and Arguments

Q:

A large number of people in ward X of the city are diagnosed to be suffering from a fatal malaria type.

Courses of Action:

I. The city municipal authority should take immediate steps to carry out extensive fumigation in ward X.

II. The people in the area should be advised to take steps to avoid mosquito bites.

A) Only I follows	B) Only II follows
C) Neither I nor II follows	D) Both I and II follow

Answer & Explanation Answer: D) Both I and II follow

Explanation:

Clearly, prevention from mosquitoes and elimination of mosquitoes are two ways to prevent malaria. So, both the courses follow.

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Filed Under: Statement and Courses of Action

Q:

The average of six numbers is x and the average of three of these is y. If the average of the remaining three is z, then :

A) x = y + z	B) 2x = y + z
C) 3x = 2y - 2z	D) none of these

Answer & Explanation Answer: B) 2x = y + z

Explanation:

Clearly, we have : x = (3y + 3z ) / 6 or 2x = y + z.

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Filed Under: Average

Q:

The average of five consecutive odd numbers is 61. What is the difference between the highest and lowest numbers :

A) 4	B) 8
C) 12	D) 16

Answer & Explanation Answer: B) 8

Explanation:

Let the numbers be x, x + 2, x + 4, x + 6 and x + 8.

Then [x + (x + 2) + (x + 4) + (x + 6) + (x + 8) ] / 5 = 61.

or 5x + 20 = 305 or x = 57.

So, required difference = (57 + 8) - 57 = 8

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Filed Under: Average

Q:

A team of 8 persons joins in a shooting competition. The best marksman scored 85 points. If he had scored 92 points, the average score for the team would have been 84. The number of points, the team scored was :

A) 665	B) 657
C) 658	D) 678

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