12th Grade > Physics
ATOMS AND NUCLEI MCQs
Atoms, Nuclei (12th Grade)
Total Questions : 60
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Answer: Option D. -> Violet
:
D
E5−E1=ΔE51
ΔE51>ΔE42 Violet color has more energy than Blue color while all colors in the option have less energy than Blue color
∴ Violet
:
D
E5−E1=ΔE51
ΔE51>ΔE42 Violet color has more energy than Blue color while all colors in the option have less energy than Blue color
∴ Violet
Answer: Option B. -> 30 minutes
:
B
NN0=(12)tT⇒(116)=(12)2T⇒(12)4=(12)2T
⇒ T = 0.5 hour = 30 minutes.
:
B
NN0=(12)tT⇒(116)=(12)2T⇒(12)4=(12)2T
⇒ T = 0.5 hour = 30 minutes.
Answer: Option A. -> 36×1023,48×1023,36×1023
:
A
Since the number of protons, neutrons and electrons in an atom of 6C14 are 6, 8 and 6 respectively. As 14 gm of 6C14 contains 6×1023 atoms, therefore the numbers of protons, neutrons and electrons in 14 gm of 6C14 are 6×6×1023,=36×1023,8×6×1023=48×1023,6×6×1023=36×1023.
:
A
Since the number of protons, neutrons and electrons in an atom of 6C14 are 6, 8 and 6 respectively. As 14 gm of 6C14 contains 6×1023 atoms, therefore the numbers of protons, neutrons and electrons in 14 gm of 6C14 are 6×6×1023,=36×1023,8×6×1023=48×1023,6×6×1023=36×1023.
Answer: Option C. -> 3Li7
:
C
5B10+0n1→3Li7+2He4.
:
C
5B10+0n1→3Li7+2He4.
Answer: Option B. -> 2.112˙A
:
B
rn∝n2
r2r1=2212=4
r2=4r
=4×0.528
=2.112˙A
:
B
rn∝n2
r2r1=2212=4
r2=4r
=4×0.528
=2.112˙A
Answer: Option C. -> L1=L22
:
C
L=nh2π Hence L1∝n1
L2∝n2
L2L1=n2n1=21 L1=L22
:
C
L=nh2π Hence L1∝n1
L2∝n2
L2L1=n2n1=21 L1=L22
Answer: Option C. -> S
:
C
2πrn=nλ
n=1
2πr1=λ
λ=2πr1=S
:
C
2πrn=nλ
n=1
2πr1=λ
λ=2πr1=S
Answer: Option B. -> 5 : 27
:
B
λ1=43R λ2=365R
λ1λ2=43×536=527
:
B
λ1=43R λ2=365R
λ1λ2=43×536=527
Answer: Option B. -> λ3=λ1×λ2λ2+λ1
:
B
ECA=ECB+EBA
hcλ3=hcλ1+hcλ2
λ3=λ1×λ2λ2+λ1
:
B
ECA=ECB+EBA
hcλ3=hcλ1+hcλ2
λ3=λ1×λ2λ2+λ1
Answer: Option D. -> n2
:
D
Bohr radius r=∑0n2h2πZme2;∴r∞n2
:
D
Bohr radius r=∑0n2h2πZme2;∴r∞n2