Answer:
halve the slit separation
Explanation:
As we know that
In YDS experiment, the equation of fringe width is as follows

where,
D denotes the separation in the middle of screen and slits
d denotes the distance in the middle of two slits
And to increase the Δx we have to decrease the d i.e, the distance between the two slits
Hence, the first option is correct
Answer:
2.5
Explanation:
The capacitance of a parallel-plate capacitor filled with dielectric is given by

where
k is the dielectric constant
is the capacitance of the capacitor without dielectric
In this problem,
is the capacitance of the capacitor in air
is the capacitance with the dielectric inserted
Solving the equation for k, we find

Answer:
Yes, the value will be the same.
Explanation:
Yes, or at least to some degree, that value of K will remain the same. You're looking for a difference in absorbance, and the difference should be visible at all wavelengths, not only at the limit. That being said, resolution varies, and if we don't read the value to the maximum, we can get a less accurate reading.