Pls explain the following VERY BASIC question with REASON / CONCEPT involved in it , the answers are given....
1. One brass plate is inserted b/w two charges.The force between the two charges will :
i. Remain the same
ii Increase
iii. Decrease
iv. Fluctuate
Ans given : ii [ the book can have mistakes ..so pls tell the ans which u think is rt..and of course its concept also ! ]
My doubt : [ How ? ]
2. Two negatively charged particles of unit magnitude and charge q are placed along a straight line.If charge q is placed at the midpoint b/w charges , then q will be in :
i. Stable Equlibrium
ii. Unstable Equlibrium
iii. Neutral Equlibrium
iv. None of the above
Ans given : ii
My doubt : [ Why not i ? ]
3. Four equal positive charges are placed at the respective vertices of a square having a point charge Q at the centre [ centre of the square ]..then Q :
i.Must NOT be in equlibrium
ii.Must be in stable equlibrium
iii..Must be in neutral equlibrium
iv..Must be in unstable equlibrium
Ans given : iv
My doubt : [ Why not ii ? ]
4. For a METALLIC Conductor,dielectric constant :
i.Must be zero
ii.Must not be infinity
iii.Must be infinity
iv.May be infinity
Ans given : iv
My doubt : [ Why not iii ? ]
5.A dimensionless body having a physical quantity varies as 1r2 , where r : distance from the body . The physical quantity may be :
i.Gravitational Potnetial
ii.Electric Field
iii.Gravitational Field
iv.None of the above
Ans given : ii
My doubt : [ Why not ii and iii ? ]