The emission spectrum of hydrogen discovered first and the region of the electromagnetic spectrum in which it belongs, respectively are

• Lyman, ultraviolet

• Lyman, visible

• Balmer, ultraviolet

• Balmer, visible

The electronic configuration of Cu is

• [Ne] 3s²,3p⁶,3d⁹,4s²

• [Ne] 3s²,3p⁶, 3d¹⁰, 4s¹

• [Ne] 3s²,3p⁶, 3d³,4s², 4p⁶

• [Ne] 3s²,3p⁶,3d⁵,4s²,4p⁴

As per de-Broglie's formula a macroscopic particle of mass 100 g and moving at a velocity of 100 cm s^-1 will have a wavelength of

• 6.6 x 10^-29 cm

• 6.6 x 10^-30 cm

• 6.6 x 10^-31 cm

• 6.6 x 10^-32 cm

4.

For one mole of an ideal gas, the slope of V vs. T curve at constant pressure of 2 atm is X L mol^-1 K^-1.The value of the ideal universal gas constant 'R' in terms of X is

• X L atm  mol^-1 K^-1

• x/2 L atm  mol^-1 K^-1

• 2X L atm  mol^-1 K^-1

• 2X atm L^-1 mol^-1 K^-1

At a certain temperature the time-required for the complete diffusion of 200 mL of H₂ gas is 30 min. The time required for the complete diffusion of 50 mL of O₂ gas at the same temperature will be

• 60min

• 30min

• 45min

• 15min

The correct order of decreasing H-C-H angle in the following molecule is

• I> II> III

• II> I> III

• III> II> I

• I> III> II

During the emission of a positron from a nucleus, the mass number of the daughter element remains the same but the atomic numbe

• is decreased by 1 unit

• is decreased by 2 units

• is increased by 1 unit

• remains unchanged

$\mathrm{\beta }$-emission is always accompanied by

• formation of antineutrino and $\mathrm{\alpha }$-particle

• emission of $\mathrm{\alpha }$-particle and $\mathrm{\gamma }$-ray

• formation of antineutrino and $\mathrm{\gamma }$-ray

• formation of antineutrino and positron

Four gases P, Q. R and S have almost same values of 'b' but their 'a' values (a, b are van der Waals' constants) are in the order Q < R < S < P. At a particular temperature, among the four gases, the most easily liquefiable one is

• P

• Q

• R

• S

The compound that will have a permanent dipole moment among the following is

• I

• II

• III

• IV