Calculate the uncertainty in the velocity of an electron when the uncertainty in position is $0.1 \mathrm{nm}$.

(report your answer(up to two decimal places) in multiple of ${10}^5 \mathrm{m} {\mathrm{s}}^{-1}$)

In an experiment to measure the charge on an electron, the following values of charge were found on the oil droplets: $-1.6\times {10}^{-19} ,-2.4\times {10}^{-19} ,-4.0\times {10}^{-19}$ (in coulomb).

What values of the electric charge would be indicated by these results? If the answer is of form $-\mathrm{y}\times {10}^{-19}$, report the value of $\mathrm{y}$.

An electron beam can undergo diffraction by crystals. Through what potential should a beam of electrons be accelerated so that its wavelength becomes equal to $1.54 \mathrm{\AA }$? Values of ${\mathrm{m}}_e=9.1\times {10}^{-31 }\mathrm{kg}$ and $\mathrm{h}=6.62\times {10}^{-34} \mathrm{J}.\mathrm{s}$.

Give answer after multiplying with 10 and rounding off to the nearest integer value.