1
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

If the work function for the photoelectron emission of a metal is 3.75 eV, then the threshold wavelength of the radiation needed for the ejection of the electron is approximately

A
315 nm
B
280 nm
C
330 nm
D
290 nm
2
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

With increasing principal quantum number, the energy difference between adjacent energy levels in $$\mathrm{H}$$-atom ............ .

A
decreases
B
increases
C
remain constant
D
decreases at low level of $$n$$ and increases for higher value of $$n$$
3
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

The electronegativity of the given elements increases in the order.

A
C, N, Si, P
B
N, Si, C, P
C
Si, P, C, N
D
P, Si, N, C
4
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

The first ionisation enthalpies of $$\mathrm{Mg}$$ and $$\mathrm{Al}$$ can be expected to be ............ .

A
$$\mathrm{IE}_1(\mathrm{Mg})=577.5 \mathrm{~kJ} \mathrm{~mol}^{-1}, \mathrm{IE}_1(\mathrm{Al})=577.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$$
B
$$\mathrm{IE}_1(\mathrm{Mg})=577.5 \mathrm{~kJ} \mathrm{~mol}^{-1}, \mathrm{IE}_1(\mathrm{Al})=737.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$$
C
$$\mathrm{IE}_1(\mathrm{Mg})=737.7 \mathrm{~kJ} \mathrm{~mol}^{-1}, \mathrm{IE}_1(\mathrm{Al})=737.7 \mathrm{~kJ} \mathrm{~mol}^{-1}$$
D
$$\mathrm{IE}_1(\mathrm{Mg})=737.7 \mathrm{~kJ} \mathrm{~mol}^{-1}, \mathrm{IE}_1(\mathrm{Al})=577.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$$