An X-ray tube is operated at 66 kV. Then, in the continuous spectrum of the emitted X-rays
Here, V=66 kV=66000 V
Now, λmin=hceV=6.6×10−34×3×1081.6×10−19×66,000=1.87×10−11 m=0.0187 nm
Since wavelength 0.01 nm is less than λmin, it will be absent from the continuous spectrum.
Hence, the correct choice is (d).