A ball is dropped onto a horizontal surface from a height of 36 cm. After bouncing several times it comes to rest covering a total distance of 100 cm measured in a vertical direction. The percentage loss in its kinetic energy after its first impact is

(a) 36 (b) 64 (c) 53 (d) 96 

In and atom an electron excites to the fourth orbit. When it jumps back to the energy levels a spectrum is formed. Total number of spectral lines in this spectrum would be 

(A)   3

(B)   4

(C)   5

 (D)   6 

A thin annular metal disc of inner and outer radii R₁ and R₂  respectively, is freely suspended from a point on its outer circumference. The length of the corresponding equivalent simple pendulum is

The variation of amplitude A with respect to time t is shown as

Which one of the following statements is not a tautology ?

(1)  P → (p ∨ q)

(2)   (p ∧ q) → (~p) ∨ q

(3)  (p  ∧ q) → p 

(4)   (p ∨ q) → (p) ∨ (~q) 

It is required to decide the ratio (e₁ / e₂) by sum and difference method also. Four cells with different values of emf E are available. One must use a cell of emf E equal to 

(a) 1.40 V  (b) 2.0 V  (c) 4.5 V  (d) 1.08 V 

If the threshold of hearing is assumed to be the reference (0 dB), then the threshold of pain is taken to be 120 dB. Let the corresponding sound intensities be I₀ and I respectively. Then I₀/I is

(a) 120 (b) 10¹² (c) 10^-12 (d) 10^1.2 

The frequency of the pendulum having maximum amplitude is 

(a)  f₀ / 2 

(b)  f₀ 

(c)   2 f₀ 

(d)  not related to  f₀

A vertical narrow wire is illuminated with laser. Alternate dark and bright bands are formed on a graph paper pasted on a distant wall. Indicate the correct statement/s. 

(a)  making appropriate measurements, it is possible to determine the diameter of the wire 

(b)  this phenomenon exhibits that light does not follow rectilinear paths 

(c)  this is a case of Fraunhoffer diffraction 

(d)  this is a case of interference of an infinitely large number of Huygens’s secondary waves leading to a diffraction pattern

Two new and different cells having emf v₁ and v₂ have their balance points P₁ and P₂ respectively, then

(a)   v₁ > v₂ 

(b)  v₁ < v₂ 

(c)  v₁ = v₂ 

(d)  insufficient data