Assertion : ${}_{11}{}^{22}\mathrm{Mg}$ emits a positron giving ${}_{12}{}^{22}\mathrm{Mg}$.

Reason : In β⁺ emission neutron is transformed into proton.

• If both assertion and reason are true and the reason is the correct explanation of the assertion.

• If both assertion and reason are true and the reason is not the correct explanation of the assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Which of the following arrangements is possible?

• n	l	m	s
  5	2	2	$+\frac{1}{2}$

• n	l	m	s
  2	2	0	$-\frac{1}{2}$

• n	l	m	s
  3	-2	1	$+\frac{1}{2}$

• n	l	m	s
  0	0	1	$+\frac{1}{2}$

Which of the following is the correct sequence of atomic weights of the given elements?

• Ni> Co> Fe

• Fe> Co> Ni

• Co> Fe> Ni

• Co> Ni> Fe

664.

Assertion : Hydrogen nuclei combines to form helium nuclei then energy is released.

Reason: Binding energy/nucleon of He is greater than hydrogen.

• If both Assertion and Reason are true and Reason is the correct explanation of Assertion

• If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

• If Assertion is true but Reason is false.

• If Assertion is false but Reason is true.

Assertion : Water is used as a moderator in nuclear reactor.

Reason : Moderator is a light substance that absorb neutrons.

• If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

• If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

• If Assertion is true but Reason is false.

• If Assertion is false but Reason is true.

Assertion : Ionisation potential of B (atomic no.5) is less than Be (atomic no. 4).

Reason : The first electron released from Be is of p-orbital but that from B is of s-orbital.

• If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

• If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

• If Assertion is true but Reason is false.

• If Assertion is false but Reason is true.

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

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 × 10^-29 cm

• 6.6 × 10^-30 cm

• 6.6 × 10^-31 cm

• 6.6 × 10^-32 cm

Assertion: For Balmer series of hydrogen spectrum, the value n₁ = 2 and n₂ = 3, 4, 5.
Reason: The value of n for a Line in Balmer series of hydrogen spectrum having the highest wavelength is 4 and 6.

• If both assertion and reason are true and reason is a correct explanation of the assertion.

• If both the assertion and reason are true but the reason is not a correct explanation of the assertion.

• If the assertion is true but the reason is false.

• If both the assertion and reason are false.

Assertion: Absolute values of the internal energy of substances can not be determined.
Reason: It is impossible to determine the exact values of constituent energies of the substances.

• If both assertion and reason are true and reason is a correct explanation of the assertion.

• If both the assertion and reason are true but the reason is not a correct explanation of the assertion.

• If the assertion is true but the reason is false.

• If both the assertion and reason are false.