1
JEE Main 2023 (Online) 12th April Morning Shift
Numerical
+4
-1

Values of work function (W$$_0$$) for a few metals are given below

Metal Li Na K Mg Cu Ag
W$$_0$$/eV 2.42 2.3 2.25 3.7 4.8 4.3

The number of metals which will show photoelectric effect when light of wavelength $$400 \mathrm{~nm}$$ falls on it is ___________

Given: $$\mathrm{h}=6.6 \times 10^{-34} \mathrm{~J} \mathrm{~s}$$

$$c=3 \times 10^{8} \mathrm{~ms}^{-1}$$

$$e=1.6 \times 10^{-19} \mathrm{C}$$

2
JEE Main 2023 (Online) 11th April Evening Shift
Numerical
+4
-1

The number of correct statements from the following is ___________.

A. For $$1 \mathrm{s}$$ orbital, the probability density is maximum at the nucleus

B. For $$2 \mathrm{s}$$ orbital, the probability density first increases to maximum and then decreases sharply to zero.

C. Boundary surface diagrams of the orbitals encloses a region of $$100 \%$$ probability of finding the electron.

D. p and d-orbitals have 1 and 2 angular nodes respectively.

E. probability density of p-orbital is zero at the nucleus

3
JEE Main 2023 (Online) 10th April Evening Shift
Numerical
+4
-1

The electron in the $$\mathrm{n}^{\text {th }}$$ orbit of $$\mathrm{Li}^{2+}$$ is excited to $$(\mathrm{n}+1)$$ orbit using the radiation of energy $$1.47 \times 10^{-17} \mathrm{~J}$$ (as shown in the diagram). The value of $$\mathrm{n}$$ is ___________

Given: $$\mathrm{R}_{\mathrm{H}}=2.18 \times 10^{-18} \mathrm{~J}$$

4
JEE Main 2023 (Online) 10th April Morning Shift
Numerical
+4
-1

The number of incorrect statement/s about the black body from the following is __________

(A) Emit or absorb energy in the form of electromagnetic radiation.

(B) Frequency distribution of the emitted radiation depends on temperature.

(C) At a given temperature, intensity vs frequency curve passes through a maximum value.

(D) The maximum of the intensity vs frequency curve is at a higher frequency at higher temperature compared to that at lower temperature.