A 600 W mercury lamp emits monochromatic radiation of wavelength 331.3 nm. How many photons are emitted from the lamp per second? (h = 6.626x 10^-34 J-s; velocity of light = 3x10⁸ ms^-1)

• 1 x 10¹⁹

• 1 x 10²⁰

• 1 x 10²¹

• 1 x 10²³

312.

In the electronic structure of H₂SO₄ , the total number of unshared electrons is

• 20

• 16

• 12

• 8

Which of the following relation is correct ?

• I^st IE of C > I^st IE of B

• I^st IE of C < I^st IE of B

• II^nd IE of C > II^nd IE of B

• Both (b) and (c)

Considering H₂O as weak field ligand, the number of unpaired electrons in [Mn(H₂O)₆] will be (Atomic number of Mn = 25)

• five

• two

• four

• three

The quantum numbers +$\frac{1}{2}$ and -$\frac{1}{2}$ for the electron spin represent

• rotation of the electron in clockwise and anticlockwise direction respectively

• rotation of the electron in anticlockwise and clockwise direction respectively

• magnetic moment of the electron pointing up and down respectively

• two quantum mechanical spin states which have no classical analogues

What is the wave number of 4^th line in Balmer series of hydrogen spectrum ? (R =1,09,677 cm^-1)

• 24630 cm^-1

• 24360 cm^-1

• 24730 cm^-1

• 24372 cm^-1

Heisenberg uncertainty principle can be explained as

• $∆\mathrm{x} \ge \frac{∆\mathrm{P} \times \mathrm{h}}{4\mathrm{\pi }}$

• $∆\mathrm{x} \times ∆\mathrm{P} \ge \frac{\mathrm{h}}{4\mathrm{\pi }}$

• $∆\mathrm{x} \times ∆\mathrm{P} \ge \frac{\mathrm{h}}{\mathrm{\pi }}$

• $∆\mathrm{P} \ge \frac{\mathrm{\pi h}}{∆\mathrm{x}}$

The de-Broglie wavelenght of a particle with mass 1 kg and velocity 100 m/s is

• 6.6 x 10^-33 m

• 6.6 x 10^-36 m

• 3.3 x 10³³ m

• 3.3 x 10^-36 m

Neutron is discovered by

• Chadwick

• Rutherford

• Yukawa

• Dalton

What is X in the following nuclear reaction?

₇N¹⁴ + ₁H¹ $\to$₈O¹⁵ + X

• ₀n¹

• _-1e⁰

• ₊₁e⁰

• $\mathrm{\gamma }$