1
JEE Main 2021 (Online) 25th July Morning Shift
Numerical
+4
-1
A source of monochromatic radiation of wavelength 400 nm provides 1000 J of energy in 10 seconds. When this radiation falls on the surface of sodium, x $$\times$$ 1020 electrons are ejected per second. Assume that wavelength 400 nm is sufficient for ejection of electron from the surface of sodium metal. The value of x is ______________. (Nearest integer)

(h = 6.626 $$\times$$ 10$$-$$34 Js)
2
JEE Main 2021 (Online) 20th July Evening Shift
Numerical
+4
-1
The wavelength of electrons accelerated from rest through a potential difference of 40 kV is x $$\times$$ 10$$-$$12 m. The value of x is ___________. (Nearest integer)

Give : Mass of electron = 9.1 $$\times$$ 10$$-$$31 kg

Charge on an electron = 1.6 $$\times$$ 10$$-$$19 C

Planck's constant = 6.63 $$\times$$ 10$$-$$34 Js
3
JEE Main 2021 (Online) 20th July Morning Shift
Numerical
+4
-1
The Azimuthal quantum number for the valence electrons of Ga+ ion is ___________.

(Atomic number of Ga = 31)
4
JEE Main 2021 (Online) 17th March Morning Shift
Numerical
+4
-1
A certain orbital has n = 4 and mL = $$-$$3. The number of radial nodes in this orbital is ____________. (Round off to the Nearest Integer).