1. A
AN
NS
SW
WE
ER
RS
S
O
OB
BJ
JE
EC
CT
TI
IV
VE
E U
UN
NS
SO
OL
LV
VE
ED
D L
LE
EV
VE
EL
L –
– I
I
1. (d) 2. (d)
3. (c) 4. (d)
5. (d) 6. (a), (b), (c), (d)
7. (b) 8. (d)
9. (d) 10. (c)
11. (d) 12. (d)
13. (a) 14. (c)
15. (b)
O
OB
BJ
JE
EC
CT
TI
IV
VE
E U
UN
NS
SO
OL
LV
VE
ED
D L
LE
EV
VE
EL
L –
– I
II
I
1. (d) 2. (b)
3. (a) 4. (c)
5. (a) 6. (b)
7. (a) 8. (c)
9. (a) 10. (d)
11. (a) 12. (b)
13. (d) 14. (b)
15. (c)
S
SU
UB
BJ
JE
EC
CT
TI
IV
VE
E U
UN
NS
SO
OL
LV
VE
ED
D (
(C
C.
.B
B.
.S
S.
.E
E.
.)
) L
LE
EV
VE
EL
L –
– I
I
1. 6572 Å, 4870 Å, 4348Å, 4109Å.
2. 1 2.0
E  MeV
2 8.0
E  MeV
3. 11
3.55 10
 m
4. (i) 1225Å (ii) 48 eV

2. (ii) 122 V .
5. 0.27Å
6. (a) + 3.4 eV (b) –6.8 eV
(c) (b) is change (d) 1217 Å.
7. (a) 27.6 keV (b) of the order of 30 kV
8. 4 1
1.23 10 s

9. 238 234 4
90
92 2 ( )
U Th He Q

   Q 4.26
 MeV
10. 41
20
( ) 8.359
n
S Ca  MeV
27
13
( ) 13.05
n
S Al  MeV.
S
SU
UB
BJ
JE
EC
CT
TI
IV
VE
E U
UN
NS
SO
OL
LV
VE
ED
D L
LE
EV
VE
EL
L –
– I
II
I
1. 54.4 ( )
b
E eV He

2. 123, 2.86 and 0.186 pm
3. 0.45 KeV
4. 39.2 MeV, 5.6 MeV
5. 2.21 MeV
6. (a) 24
3.24 10
 (b) 1.264 kg/day
(c) 1264 kg
7. (a) (b) 0.028 min-1
(Approx)
(c) 25 min (approx)
8. (a) 
 (b) 64 min.
9. 1800y
10. 5
4.9 10
B T

 
11. (a) 16
6.25 10
 (b) 8 1
1.3 10 ms

(c) 0.248 Å
12. 1 2
/ 0.1
  
13. (i) 3.4 eV (ii) 6.63
  Å
14. (i) 14.43 sec (ii) 40
t  sec.
15. (a) 5
10 per sec (b) 285.1

3. (c) 111 sec.
S
SU
UB
BJ
JE
EC
CT
TI
IV
VE
E U
UN
NS
SO
OL
LV
VE
ED
D L
LE
EV
VE
EL
L –
– I
II
II
I
1. (a) 1 2
1 0
2
2 1
( ) ( )
t t
N
N t e e
 

 
 
(b) 2 1
2 1
ln( / )
t
 

  
2. 0.0625 , 0.03125
C C
 
3. 51.4%, 2.13%, 46.45%.
4. (a) A = 232, Z = 90 (b) 5.336 MeV, 7.86 MeV
5. max
4, 18800
n    Å
6. E = 150.9 eV
7. (i) 8
3 10
 m (ii) 11
2.5 10
 m
8. 14
6.3 10
 Nm-2
.
9. 1
r , pm 6
, 10
v m/s ,
T eV b
E , eV ,
i
 V 1
 , V  , nm
H 52.9 2.18 13.6 13.6 13.6 10.2 121.5
He 26.5 4.36 54.5 54.5 54.5 40.8 30.4
10. (a) 0.285 pm, 2.53 KeV, 0.65 nm (b) 106 pm, 6.8 eV, 0.243 m

11. 4
6.9 10
 s.
12. 1.342 kg
13. 3.125 × 1016
kg.
14. 34
6.43 10
  Joule second.
15. = 0.148 metre.
S
SU
UB
BJ
JE
EC
CT
TI
IV
VE
E U
UN
NS
SO
OL
LV
VE
ED
D L
LE
EV
VE
EL
L
1. 5
3.32 10
 watt
2. (a) 0
1
[ ( ) ]
t
N N e
     

(b) 0 0
3
, 2
2
N N N N
  .
3. (a) 2 4, 217.6 , 10.58
n Z eV eV
   (b) 11
6.25 10 , , 5.0
Zero eV
 .
4. 4
3.847 10
 Kg

4. 5. 6.25 , 227.62
MeV a.m.u.
6. (i) . ,
y
x z
x x x x y x y y
dN
dN dN
N N N N
dt dt dt
      
(ii) 16.485 (iii) 19
1.92 10
x
N   , 19
2.32 10
z
N   .
7. (a) 3
Z  (b) min 4052.3 nm
 
8. 42
Z 
9. 6.947sec.
10.
(
a
)
(
b
)
i
A
n
o
d
e
P
o
t
e
n
t
i
a
l
8A



A
11. 3.861
12. max 0.55
K  eV.