Two parallel plate capacitors of capacitances C and 2C are connected in parallel and charged to a potential difference $V_{0}$ . The battery is then disconnected and the region between the plates of the capacitor C is completely filled with a material of dielectric constant 2. The potential difference across the capacitors now becomes:

Q. The threshold frequency for a certain photosensitive metal is

ν_{0}

. When it is illuminated by light of frequency

ν = 2 ν_{0}

, the stopping potential for photoelectric current is

V_{0}

. What will be the stopping potential when the same metal is illuminated by light of frequency

ν = 3 ν_{0}

Join BYJU'S Learning Program

If the gravitational potential on the surface of earth is V0 then potential at a point at height half of the radius of earth is

The correct option is B 23V0ur=−GMmr(Gravitationalpotential)=v0 at surfaceat height h∼r2ur2∼−GMm3r2=23V0Hence,option (B) is correct answer.

If the gravitational potential on the surface of earth is $V_{0}$ then potential at a point at height half of the radius of earth is

The correct option is B $\frac{2}{3} V_{0}$
$u_{r} = \frac{- G M m}{r} (G r a v i t a t i o n a l p o t e n t i a l)$
$= v_{0}$ at surface
at height $h \sim \frac{r}{2}$
$u_{r^{2}} \sim \frac{- G M m}{\frac{3 r}{2}} = \frac{2}{3} V_{0}$
Hence,
option $(B)$ is correct answer.