Solved papers for JEE Main & Advanced JEE Main Paper (Held On 19 May 2012)

done JEE Main Paper (Held On 19 May 2012) Total Questions - 2

• question_answer1) A charge of total amount Q is distributed over two concentric hollow spheres of radii r and R (R > r) such that the surface charge densities on the two spheres are equal. The electric potential at the common centre is     JEE Main  Online Paper (Held On 19  May  2012)
  A)
  \[\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{\left( R-r \right)Q}{\left( {{R}^{2}}+{{r}^{2}} \right)}\]   
  done clear
  B)
                         \[\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{\left( R+r \right)Q}{2\left( {{R}^{2}}+{{r}^{2}} \right)}\]
  done clear
  C)
                         \[\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{\left( R+r \right)Q}{\left( {{R}^{2}}+{{r}^{2}} \right)}\]  
  done clear
  D)
                         \[\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{\left( R-r \right)Q}{\left( {{R}^{2}}+{{r}^{2}} \right)}\]
  done clear
  View Answer play_arrow

• question_answer2) The flat base of a hemisphere of radius a with no charge inside it lies in a horizontal plane. A uniform electric field E is applied at an angle\[\frac{\pi }{4}\]with the vertical direction. The electric flux through the curved surface of the hemisphere is     JEE Main  Online Paper (Held On 19  May  2012)
  A)
  \[\pi {{a}^{2}}E\]                             
  done clear
  B)
                         \[\frac{\pi {{a}^{2}}E}{\sqrt{2}}\]
  done clear
  C)
                         \[\frac{\pi {{a}^{2}}E}{2\sqrt{2}}\]                           
  done clear
  D)
                         \[\frac{\left( \pi +2 \right)\pi {{a}^{2}}E}{{{\left( 2\sqrt{2} \right)}^{2}}}\]
  done clear
  View Answer play_arrow