Oscillations (SHM) · JEE Main previous year questions

2012 2 questions

1. Q452012 · 7 May 2012 · Shift 1

   Following are expressions for four plane simple harmonic waves (i) $y_1=A\cos 2\pi \left(n_{1}t+\frac{x}{{\lambda }_1}\right)$ (ii) $y_2=A\cos \left[2\pi \left(n_{1}t+\frac{x}{{\lambda }_1}\right)+\pi \right]$ (iii) $y_3=A\cos 2\pi \left(n_{2}t+\frac{x}{{\lambda }_2}\right)$ (iv) $y_4=A\cos 2\pi \left(n_{2}t-\frac{x}{{\lambda }_2}\right)$ The pairs of waves which will produce destructive interference and stationary waves respectively in a medium, are

   1. A.(iii, iv), (i, ii)
   2. B.(i, iii), (ii, iv)
   3. C.(i, iv), (ii, iii)
   4. D.(i, ii), (iii, iv)
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   Answer: D

2. Q462012 · 7 May 2012 · Shift 1

   This question has Statement 1 and Statement 2. Of the four choices given after the Statements, choose the one that best describes the two Statements. Statement 1: In the resonance tube experiment, if the tuning fork is replaced by another identical tuning fork but with its arm having been filed, the length of the air column should be increased to obtain resonance again. Statement 2: On filing the arms, the frequency of a tuning fork increases.

   1. A.Statement 1 is true, Statement 2 is true, Statement 2 is a correct explanation of Statement 1.
   2. B.Statement 1 is true, Statement 2 is false.
   3. C.Statement 1 is false, Statement 2 is true.
   4. D.Statement 1 is true, Statement 2 is true, Statement 2 is not a correct explanation of Statement 1.
   Show answer

   Answer: C