KCET 2021 Physics Solved Paper

Given, m=2g=2×10−3‌kg
E=(300NC−1)

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i

At, x=0,(KE)1=0 and x=0.5m,(KE)2=0.12J From work-energy theorem, work done = change in kinetic energy
⇒ Force × displacement =Δ‌KE
QE×d=KE2−KE1
⇒ Q×300×0.5=0.12
or Q=

0.12

300×0.5

=800µC
The charge Q is moving in the direction of electric field. Hence, it is positive.