Question 256: Electrostats & Capacitance

Question

A simple pendulum of length L is placed between the plates of a parallel plate capacitor having electric field
E, as shown in figure. Its bob has mass m and charge q. The time period of the pendulum is given by :

Accepted Answer

$$t = 2\pi \sqrt {{L \over {{g_{eff}}}}} $$
$$ \Rightarrow {g_{eff}} = \sqrt {{g^2} + {{\left( {{{gE} \over m}} \right)}^2}} $$
$$ \Rightarrow t = 2\pi \sqrt {{L \over {\sqrt {{g^2} + {{\left( {{{qE} \over m}} \right)}^2}} }}} $$

Answer

$$2\pi \sqrt {{L \over {\sqrt {{g^2} - {{{q^2}{E^2}} \over {{m^2}}}} }}} $$

Answer

$$2\pi \sqrt {{L \over {\left( {g + {{qE} \over m}} \right)}}} $$

Answer

$$2\pi \sqrt {{L \over {\sqrt {{g^2} + {{{q^2}{E^2}} \over {{m^2}}}} }}} $$

Answer

$$2\pi \sqrt {{L \over {\left( {g - {{qE} \over m}} \right)}}} $$

Electrostats & Capacitance

A simple pendulum of length L is placed between the plates of a parallel plate capacitor having electric field E, as shown in figure. Its bob has mass m and charge q. The time period of the pendulum is given by :

Choose the correct answer: