If the displacements of a particle at time t is given by s2 = at2

Subject

Mathematics

Class

JEE Class 12

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

11.

The function f(x) = 1 - x3 - x5 is decreasing for :

  • 1  x  5

  • x  1

  • x  1

  • all values of x


12.

ddxxx is equal to :

  • logx

  • logex

  • xxlogx

  • xxlogex


Advertisement

13.

If the displacements of a particle at time t is given by s2 = at2 + 2bt + c, then acceleration varies as :

  • 1s2

  • 1s

  • 1s3

  • s3


C.

1s3

Given that, s = at2 + 2bt +cOn differentiating w.r.t. t, we get     dsdt = 12at2 + 2bt + c2at + 2b dsdt = at +bat2 + 2bt + c = at + bsAgain differentiating, we get    d2sdt2 = sa - at + bdsdts2           = sa - at +bat +bss2           = s2a - at + b2s3           = at2 + 2bt +ca - at + b2s3           = ac - b2s3 Acceleration varies as 1s3.


Advertisement
14.

If PQ and PR are the two sides of a triangle, then the angle between them which gives maximum area of the triangle, is :

  • π

  • π3

  • π4

  • π2


Advertisement
15.

The function y = a(1 - cos(x)) is maximum when x is equal to

  • π

  • π2

  • - π2

  • π6


16.

If tan-1x + tan-1y + tan-1z = π then x + y + z is :

  • xyz

  • 0

  • 1

  • 2xyz


17.

If θ = sin-1sin- 600°, then one of the possible values of θ is :

  • π3

  • π2

  • 2π3

  • - 2π3


18.

A force of magnitude 5 unit acting along the vector 2i^ - 2j^ + k^ displaces the point of application from (1, 2, 3) to (5, 3, 7). Then the work done is :

  • 50/7 unit

  • 50/3 unit

  • 25/3

  • 25/4


Advertisement
19.

An unit vector perpendicular to both i^ + j^ and j^ + k^ is :

  • i^ - j^ + k^

  • i^ + j^ + k^

  • i^ + j^ - k^3

  • i^ - j^ + k^3


20.

The area of the triangle whose vertices are (1, 2, 3), (2, 5, -1) and (-1, 1, 2) is :

  • 150 sq unit

  • 145 sq unit

  • 1552 sq unit

  • 1552 sq unit


Advertisement