# a simple pendulum has a metal bob which is negatively charged.If it is allowed to oscillate above,a positively charged metallic plate,then its time period will

Mukesh Sharma
10 years ago
Due to force of attration offered by the Positive charge on the plate the priod will decrease Thanks and regards askIITians faculty mukesh sharma
Aniket Tatte
19 Points
7 years ago
Since Time Period of Simple Pendulum is given by - 2*(pi)* sqrt(L/g).When Bob is given a because charge and allowed to oscillate in electric field of positive plate the negatively charged Bob will be attracted by positively charged plate. Hence the net force in vertically downwards direction in increased. This leads to a new value of `g` Which is obviously increased. With the new increased value of `g` being used in the formula we can conclude that the expression of time period decreases as T is inversely proportional to acceleration due to gravity. Therefore time period will decrease. Hope this concept by me helps you.:-)
ABHISHEK VERMA
15 Points
5 years ago
DUE TO ATTRACTION  BETWEEN POSITIVE CHARGED PLATE AND NEGATIVELY METAL BOB ;FORCE OF ATTRACTION  BEYWEEN THEM INCREASES WHICH LEADS TO INCRECSE VALUE OF’’’’ g ‘’’’HENCE’’’’ T ‘’’’’OF METAL BOB IS DECRASES BECAUSE ‘’’’T IS INVERSELY PROPORIONAL TO g’’’’’’’
3 years ago
Dear student,

As we know the formula for the time period of a simple pendulum is, T = 2π(L/geff.)½
In the given condition the metallic bob will face electrostatic force of attraction along with the previous gravitational force in the downward direction. Due to which geff. increases.
Since T is inversely proportional to geff., the time period of oscillation of pendulum will decrease.

Hope it helps.
Thanks and regards,
Kushagra