Oscillations (SHM) · JEE Main previous year questions

2015 4 questions

1. Q312015 · 4 Apr 2015 · Shift 1

   The period of oscillation of a simple pendulum is $T=2\pi \sqrt{\frac{L}{g}}$. Measured value of L is $20.0\mathrm{cm}$ known to $1\mathrm{mm}$ accuracy and time for 100 oscillations of the pendulum is found to be $90\mathrm{s}$ using wrist watch of $1\mathrm{s}$ resolution. The accuracy in the determination of g is:

   1. A.$1\%$
   2. B.$5\%$
   3. C.$2\%$
   4. D.$3\%$
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   Answer: D

2. Q402015 · 4 Apr 2015 · Shift 1

   A pendulum made of a uniform wire of cross sectional area $A$ has time period $T$. When an additional mass $M$ is added to its bob, the time period changes to $T_M$. If the Young's modulus of the material of the wire is $Y$ then $\frac{1}{Y}$ is equal to : ($g=\text{gravitational acceleration}$)

   1. A.$\left[1-{\left(\frac{T_M}{T}\right)}^2\right]\frac{A}{Mg}$
   2. B.$\left[1-{\left(\frac{T}{T_M}\right)}^2\right]\frac{A}{Mg}$
   3. C.$\left[{\left(\frac{T_M}{T}\right)}^2-1\right]\frac{A}{Mg}$
   4. D.$\left[{\left(\frac{T_M}{T}\right)}^2-1\right]\frac{Mg}{A}$
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   Answer: C

3. Q412015 · 4 Apr 2015 · Shift 1
   
   1. A.
   2. B.
   3. C.
   4. D.
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   Answer: D

4. Q532015 · 4 Apr 2015 · Shift 1
   
   1. A.
   2. B.
   3. C.
   4. D.
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   Answer: C