WBJEE Previous Year Question Paper - 2015 | WBJEE Sample Papers, Section Wise & Full Mock Tests 2026 PDF Download

 Page 1


Physics
1. Two particles of massm
1
andm
2
; approach
each other due to their mutual gravitational
attraction only. Then,
(a) accelerations of both the particles are equal
(b) acceleration of the particle of mass m
1
is
proportional tom
1
(c) acceleration of the particle of mass m
1
is
proportional tom
2
(d) acceleration of the particle of massm
1
is inversely
proportional tom
1
2. Three bodies of the same material and
having masses m m , and 3m are at
temperatures 40°C, 50°C and 60°C,
respectively. If the bodies are brought in
thermal contact, the final temperature
will be
(a) 45°C (b) 54°C
(c) 52°C (d) 48°C
3. A satellite has kinetic energy K, potential
energy V and total energy E. Which of the
following statements is true?
(a) K V = - /2 (b) K V = /2
(c) E K = /2 (d) E K = - /2
4. An object is located 4 m from the first of two
thin converging lenses of focal lengths 2 m
and 1 m, respectively. The lenses are
separated by 3 m. The final image formed by
the second lens is located from the source at
a distance of
(a) 8.0 m (b) 5.5 m
(c) 6.0 m (d) 6.5 m
5. A simple pendulum of length L swings in a
vertical plane. The tension of the string
when it makes an angle q with the vertical
and the bob of massm moves with a speedv
is (g is the gravitational acceleration)
(a) mv L
2
/ (b) mg mv L cos / q +
2
(c) mg mv L cos / q -
2
(d) mg cos q
6. The length of a metal wire is L
1
when the
tension is T
1
and L
2
when the tension is T
2
.
The unstretched length of wire is
(a)
L L
1 2
2
+
(b) LL
1 2
(c)
T L TL
T T
2 1 1 2
2 1
-
-
(d)
T L TL
T T
2 1 1 2
2 1
+
+
7. The line AA¢ is on charged infinite
conducting plane which is
perpendicular to the plane of the
paper. The plane has a surface
density of charges and B is ball of
mass m with a like charge of
magnitudeq.B is connected by string from a
point on the lineAA¢. The tangent of angle( ) q
formed between the lineAA¢ and the string is
(a)
q
mg
s
2
0
Î
(b)
q
mg
s
pe
0
4
(c)
q
mg
s
pe 2
0
(d)
q
mg
s
e
0
8. The currentI is in the circuit shown is
(a) 1.33 A (b) zero (c) 2.00 A (d) 1.00 A
3m 4m
Source
?
A
B
A'
2V
2O 2O
2V
2O
2V
–
+
–
+
–
+
I
WB JEE
Engineering Entrance Exam
Solved Paper 2015
Page 1 of 38
Page 2


Physics
1. Two particles of massm
1
andm
2
; approach
each other due to their mutual gravitational
attraction only. Then,
(a) accelerations of both the particles are equal
(b) acceleration of the particle of mass m
1
is
proportional tom
1
(c) acceleration of the particle of mass m
1
is
proportional tom
2
(d) acceleration of the particle of massm
1
is inversely
proportional tom
1
2. Three bodies of the same material and
having masses m m , and 3m are at
temperatures 40°C, 50°C and 60°C,
respectively. If the bodies are brought in
thermal contact, the final temperature
will be
(a) 45°C (b) 54°C
(c) 52°C (d) 48°C
3. A satellite has kinetic energy K, potential
energy V and total energy E. Which of the
following statements is true?
(a) K V = - /2 (b) K V = /2
(c) E K = /2 (d) E K = - /2
4. An object is located 4 m from the first of two
thin converging lenses of focal lengths 2 m
and 1 m, respectively. The lenses are
separated by 3 m. The final image formed by
the second lens is located from the source at
a distance of
(a) 8.0 m (b) 5.5 m
(c) 6.0 m (d) 6.5 m
5. A simple pendulum of length L swings in a
vertical plane. The tension of the string
when it makes an angle q with the vertical
and the bob of massm moves with a speedv
is (g is the gravitational acceleration)
(a) mv L
2
/ (b) mg mv L cos / q +
2
(c) mg mv L cos / q -
2
(d) mg cos q
6. The length of a metal wire is L
1
when the
tension is T
1
and L
2
when the tension is T
2
.
The unstretched length of wire is
(a)
L L
1 2
2
+
(b) LL
1 2
(c)
T L TL
T T
2 1 1 2
2 1
-
-
(d)
T L TL
T T
2 1 1 2
2 1
+
+
7. The line AA¢ is on charged infinite
conducting plane which is
perpendicular to the plane of the
paper. The plane has a surface
density of charges and B is ball of
mass m with a like charge of
magnitudeq.B is connected by string from a
point on the lineAA¢. The tangent of angle( ) q
formed between the lineAA¢ and the string is
(a)
q
mg
s
2
0
Î
(b)
q
mg
s
pe
0
4
(c)
q
mg
s
pe 2
0
(d)
q
mg
s
e
0
8. The currentI is in the circuit shown is
(a) 1.33 A (b) zero (c) 2.00 A (d) 1.00 A
3m 4m
Source
?
A
B
A'
2V
2O 2O
2V
2O
2V
–
+
–
+
–
+
I
WB JEE
Engineering Entrance Exam
Solved Paper 2015
Page 1 of 38
9. A hollow sphere of external radius R and
thickness t R ( ) << is made of a metal of
densityr. The sphere will float in water, if
(a)t
R
£
r
(b)t
R
£
3r
(c)t
R
£
2r
(d)t
R
³
3r
10. A metal wire of circular cross-section has a
resistance R
1
. The wire is now stretched
without breaking, so that its length is doubled
and the density is assumed to remain the
same. If the resistance of the wire now
becomesR
2
, thenR R
2 1
: is
(a) 1 : 1 (b) 1 : 2 (c) 4 : 1 (d) 1 : 4
11. Assume that each diode as shown in the
figure has a forward bias resistance of50 W
and an infinite reverse bias resistance. The
current through the resistance150 W is
(a) 0.66 A (b) 0.05 A (c) zero (d) 0.04 A
12. The rms speed of oxygen is v at a particular
temperature. If the temperature is doubled
and oxygen molecules dissociate into
oxygen atoms, the rms speed becomes
(a) v (b) 2v
(c)2v (d) 4v
13. Two particles, A and B, having equal
charges, after being accelerated through the
same potential difference enter into a region
of uniform magnetic field and the particles
describe circular paths of radii R
1
and R
2
,
respectively. The ratio of the masses ofA and
B is
(a) R R
1 2
/ (b) R R
1 2
/
(c)( / ) R R
1 2
2
(d)( / ) R R
2 1
2
14. A large number of particles are placed
around the origin, each at a distance R from
the origin. The distance of the center of mass
of the system from the origin is
(a) equal to R
(b) less than equal to R
(c) greater then R
(d) greater than equal to R
15. A straight conductor 0.1 m long moves in a
uniform magnetic field 0.1T. The velocity of
the conductor is 15 m/s and is directed
perpendicular to the field. The emf induced
between the two ends of the conductor is
(a) 0.10 V (b) 0.15 V (c) 1.50 V (d) 15.00 V
16. A ray of light is incident at an angle i on a
glass slab of refractive index m. The angle
between reflected and refracted light is90°.
Then, the relationship betweeni andm is
(a) i =
æ
è
ç
ö
ø
÷
-
tan
1
1
m
(b) tani =m
(c)sini =m (d)cos i =m
17. Two particles A and B are moving as shown
in the figure.
Their total angular momentum about the
pointO is
(a) 9.8 kg m / s
2
(b) zero
(c) 52.7 kg m /s
2
(d) 37.9 kg m /s
2
18. A 20 cm long capillary tube is dipped
vertically in water and the liquid rises upto
10 cm. If the entire system is kept is a freely
falling platform, the length of the water
column in the tube will be
(a) 5 cm (b) 10 cm (c) 15 cm (d) 20 cm
19. A train is moving with a uniform speed of
33 m/s and an observer is approaching the
train with the same speed. If the train blows
a whistle of frequency 1000 Hz and the
velocity of sound is 333 m/s, then the
apparent frequency of the sound that the
observer hears is
(a) 1220 Hz (b) 1099 Hz (c) 1110 Hz (d) 1200 Hz
20. A photon of wavelength 300 nm interacts
with a stationary hydrogen atom in ground
state. During the interaction, whole energy of
the photon is transferred to the electron of
the atom. State which possibility is correct.
(Consider, Plank constant = ´
-
4 10
15
eVs ,
velocity of light = ´ 3 10
8
m/s, ionisation
energy of hydrogen=13.6eV)
50 O
100 O
150 O
+
–
10 V
2.2 m/s 6.5 kg
1.5 m
2.8 m 3.1 kg
3.6 m/s
A
B
O
Page 2 of 38
Page 3


Physics
1. Two particles of massm
1
andm
2
; approach
each other due to their mutual gravitational
attraction only. Then,
(a) accelerations of both the particles are equal
(b) acceleration of the particle of mass m
1
is
proportional tom
1
(c) acceleration of the particle of mass m
1
is
proportional tom
2
(d) acceleration of the particle of massm
1
is inversely
proportional tom
1
2. Three bodies of the same material and
having masses m m , and 3m are at
temperatures 40°C, 50°C and 60°C,
respectively. If the bodies are brought in
thermal contact, the final temperature
will be
(a) 45°C (b) 54°C
(c) 52°C (d) 48°C
3. A satellite has kinetic energy K, potential
energy V and total energy E. Which of the
following statements is true?
(a) K V = - /2 (b) K V = /2
(c) E K = /2 (d) E K = - /2
4. An object is located 4 m from the first of two
thin converging lenses of focal lengths 2 m
and 1 m, respectively. The lenses are
separated by 3 m. The final image formed by
the second lens is located from the source at
a distance of
(a) 8.0 m (b) 5.5 m
(c) 6.0 m (d) 6.5 m
5. A simple pendulum of length L swings in a
vertical plane. The tension of the string
when it makes an angle q with the vertical
and the bob of massm moves with a speedv
is (g is the gravitational acceleration)
(a) mv L
2
/ (b) mg mv L cos / q +
2
(c) mg mv L cos / q -
2
(d) mg cos q
6. The length of a metal wire is L
1
when the
tension is T
1
and L
2
when the tension is T
2
.
The unstretched length of wire is
(a)
L L
1 2
2
+
(b) LL
1 2
(c)
T L TL
T T
2 1 1 2
2 1
-
-
(d)
T L TL
T T
2 1 1 2
2 1
+
+
7. The line AA¢ is on charged infinite
conducting plane which is
perpendicular to the plane of the
paper. The plane has a surface
density of charges and B is ball of
mass m with a like charge of
magnitudeq.B is connected by string from a
point on the lineAA¢. The tangent of angle( ) q
formed between the lineAA¢ and the string is
(a)
q
mg
s
2
0
Î
(b)
q
mg
s
pe
0
4
(c)
q
mg
s
pe 2
0
(d)
q
mg
s
e
0
8. The currentI is in the circuit shown is
(a) 1.33 A (b) zero (c) 2.00 A (d) 1.00 A
3m 4m
Source
?
A
B
A'
2V
2O 2O
2V
2O
2V
–
+
–
+
–
+
I
WB JEE
Engineering Entrance Exam
Solved Paper 2015
Page 1 of 38
9. A hollow sphere of external radius R and
thickness t R ( ) << is made of a metal of
densityr. The sphere will float in water, if
(a)t
R
£
r
(b)t
R
£
3r
(c)t
R
£
2r
(d)t
R
³
3r
10. A metal wire of circular cross-section has a
resistance R
1
. The wire is now stretched
without breaking, so that its length is doubled
and the density is assumed to remain the
same. If the resistance of the wire now
becomesR
2
, thenR R
2 1
: is
(a) 1 : 1 (b) 1 : 2 (c) 4 : 1 (d) 1 : 4
11. Assume that each diode as shown in the
figure has a forward bias resistance of50 W
and an infinite reverse bias resistance. The
current through the resistance150 W is
(a) 0.66 A (b) 0.05 A (c) zero (d) 0.04 A
12. The rms speed of oxygen is v at a particular
temperature. If the temperature is doubled
and oxygen molecules dissociate into
oxygen atoms, the rms speed becomes
(a) v (b) 2v
(c)2v (d) 4v
13. Two particles, A and B, having equal
charges, after being accelerated through the
same potential difference enter into a region
of uniform magnetic field and the particles
describe circular paths of radii R
1
and R
2
,
respectively. The ratio of the masses ofA and
B is
(a) R R
1 2
/ (b) R R
1 2
/
(c)( / ) R R
1 2
2
(d)( / ) R R
2 1
2
14. A large number of particles are placed
around the origin, each at a distance R from
the origin. The distance of the center of mass
of the system from the origin is
(a) equal to R
(b) less than equal to R
(c) greater then R
(d) greater than equal to R
15. A straight conductor 0.1 m long moves in a
uniform magnetic field 0.1T. The velocity of
the conductor is 15 m/s and is directed
perpendicular to the field. The emf induced
between the two ends of the conductor is
(a) 0.10 V (b) 0.15 V (c) 1.50 V (d) 15.00 V
16. A ray of light is incident at an angle i on a
glass slab of refractive index m. The angle
between reflected and refracted light is90°.
Then, the relationship betweeni andm is
(a) i =
æ
è
ç
ö
ø
÷
-
tan
1
1
m
(b) tani =m
(c)sini =m (d)cos i =m
17. Two particles A and B are moving as shown
in the figure.
Their total angular momentum about the
pointO is
(a) 9.8 kg m / s
2
(b) zero
(c) 52.7 kg m /s
2
(d) 37.9 kg m /s
2
18. A 20 cm long capillary tube is dipped
vertically in water and the liquid rises upto
10 cm. If the entire system is kept is a freely
falling platform, the length of the water
column in the tube will be
(a) 5 cm (b) 10 cm (c) 15 cm (d) 20 cm
19. A train is moving with a uniform speed of
33 m/s and an observer is approaching the
train with the same speed. If the train blows
a whistle of frequency 1000 Hz and the
velocity of sound is 333 m/s, then the
apparent frequency of the sound that the
observer hears is
(a) 1220 Hz (b) 1099 Hz (c) 1110 Hz (d) 1200 Hz
20. A photon of wavelength 300 nm interacts
with a stationary hydrogen atom in ground
state. During the interaction, whole energy of
the photon is transferred to the electron of
the atom. State which possibility is correct.
(Consider, Plank constant = ´
-
4 10
15
eVs ,
velocity of light = ´ 3 10
8
m/s, ionisation
energy of hydrogen=13.6eV)
50 O
100 O
150 O
+
–
10 V
2.2 m/s 6.5 kg
1.5 m
2.8 m 3.1 kg
3.6 m/s
A
B
O
Page 2 of 38
(a) Electron will be knocked out of the atom
(b) Electron will go to any excited state of the atom
(c) Electron will go only to first excited state of the
atom
(d) Electron will keep orbiting in the ground state of
the atom
21. ParticleA moves alongX-axis with a uniform
velocity of magnitude 10 m/s. Particle B
moves with uniform velocity 20 m/s along a
direction making an angle of 60° with the
positive direction of X-axis as shown in the
figure. The relative velocity ofB with respect
to that ofA is
(a) 10 m/s along X-axis
(b)10 3m/s along Y-axis (perpendicular to X-axis)
(c)10 5m/s along the bisection of the velocities of
A and B
(d) 30 m/s along negative X-axis
22. When light is refracted from a surface, which
of its following physical parameters does not
change?
(a) Velocity
(b) Amplitude
(c) Frequency
(d) Wavelength
23. A solid maintained at t°
1
C is kept in an
evacuated chamber at temperature t°
2
C
( ) t t
2 1
>> . The rate of heat absorbed by the
body is proportional to
(a)t t
2
4
1
4
-
(b)( ) ( ) t t
2
4
1
4
273 273 + - +
(c)t t
2 1
-
(d)t t
2
2
1
2
-
24. Block B lying on a table weighs W. The
coefficient of static friction between the
block and the table ism. Assume that the cord
between B and the knot is horizontal. The
maximum weight of the block A for which
the system will be stationary is
(a)
W tanq
m
(b)m q W tan
(c)m q W 1
2
+ tan (d)m q W sin
25. The inputs to the digital circuit are as shown
below. The outputY is
(a) A B C + +
(b)( ) A B C +
(c) A B C + +
(d) A B C + +
26. Two particles A and B having different
masses are projected from a tower with same
speed. A is projected vertically upward and
B vertically downward. On reaching the
ground
(a) velocity of A is greater than that of B
(b) velocity ofB is greater than that of A
(c) both A and B attain the same velocity
(d) the particle with the larger mass attains higher
velocity
27. The work function of metals is in the range of
2eV to 5eV. Find which of the following
wavelength of light cannot be used for
photoelectric effect? (Consider, Plank
constant = ´
-
4 10
15
eVs, velocity of light
= ´ 3 10
8
m/s)
(a) 510 nm (b) 650 nm
(c) 400 nm (d) 570 nm
28. A thin plastic sheet of refractive index 1.6 is
used to cover one of the slits of a double slit
arrangement. The central point on the screen
is now occupied by what would have been the
7th bright fringe before the plastic was used. If
the wavelength of light is 600 nm, what is the
thickness (inmm) of the plastic sheet?
(a) 7 (b) 4
(c) 8 (d) 6
60°
20 m/s
A 10 m/s
B
X
B
A
Knot
?
A
B
C
Y
Page 3 of 38
Page 4


Physics
1. Two particles of massm
1
andm
2
; approach
each other due to their mutual gravitational
attraction only. Then,
(a) accelerations of both the particles are equal
(b) acceleration of the particle of mass m
1
is
proportional tom
1
(c) acceleration of the particle of mass m
1
is
proportional tom
2
(d) acceleration of the particle of massm
1
is inversely
proportional tom
1
2. Three bodies of the same material and
having masses m m , and 3m are at
temperatures 40°C, 50°C and 60°C,
respectively. If the bodies are brought in
thermal contact, the final temperature
will be
(a) 45°C (b) 54°C
(c) 52°C (d) 48°C
3. A satellite has kinetic energy K, potential
energy V and total energy E. Which of the
following statements is true?
(a) K V = - /2 (b) K V = /2
(c) E K = /2 (d) E K = - /2
4. An object is located 4 m from the first of two
thin converging lenses of focal lengths 2 m
and 1 m, respectively. The lenses are
separated by 3 m. The final image formed by
the second lens is located from the source at
a distance of
(a) 8.0 m (b) 5.5 m
(c) 6.0 m (d) 6.5 m
5. A simple pendulum of length L swings in a
vertical plane. The tension of the string
when it makes an angle q with the vertical
and the bob of massm moves with a speedv
is (g is the gravitational acceleration)
(a) mv L
2
/ (b) mg mv L cos / q +
2
(c) mg mv L cos / q -
2
(d) mg cos q
6. The length of a metal wire is L
1
when the
tension is T
1
and L
2
when the tension is T
2
.
The unstretched length of wire is
(a)
L L
1 2
2
+
(b) LL
1 2
(c)
T L TL
T T
2 1 1 2
2 1
-
-
(d)
T L TL
T T
2 1 1 2
2 1
+
+
7. The line AA¢ is on charged infinite
conducting plane which is
perpendicular to the plane of the
paper. The plane has a surface
density of charges and B is ball of
mass m with a like charge of
magnitudeq.B is connected by string from a
point on the lineAA¢. The tangent of angle( ) q
formed between the lineAA¢ and the string is
(a)
q
mg
s
2
0
Î
(b)
q
mg
s
pe
0
4
(c)
q
mg
s
pe 2
0
(d)
q
mg
s
e
0
8. The currentI is in the circuit shown is
(a) 1.33 A (b) zero (c) 2.00 A (d) 1.00 A
3m 4m
Source
?
A
B
A'
2V
2O 2O
2V
2O
2V
–
+
–
+
–
+
I
WB JEE
Engineering Entrance Exam
Solved Paper 2015
Page 1 of 38
9. A hollow sphere of external radius R and
thickness t R ( ) << is made of a metal of
densityr. The sphere will float in water, if
(a)t
R
£
r
(b)t
R
£
3r
(c)t
R
£
2r
(d)t
R
³
3r
10. A metal wire of circular cross-section has a
resistance R
1
. The wire is now stretched
without breaking, so that its length is doubled
and the density is assumed to remain the
same. If the resistance of the wire now
becomesR
2
, thenR R
2 1
: is
(a) 1 : 1 (b) 1 : 2 (c) 4 : 1 (d) 1 : 4
11. Assume that each diode as shown in the
figure has a forward bias resistance of50 W
and an infinite reverse bias resistance. The
current through the resistance150 W is
(a) 0.66 A (b) 0.05 A (c) zero (d) 0.04 A
12. The rms speed of oxygen is v at a particular
temperature. If the temperature is doubled
and oxygen molecules dissociate into
oxygen atoms, the rms speed becomes
(a) v (b) 2v
(c)2v (d) 4v
13. Two particles, A and B, having equal
charges, after being accelerated through the
same potential difference enter into a region
of uniform magnetic field and the particles
describe circular paths of radii R
1
and R
2
,
respectively. The ratio of the masses ofA and
B is
(a) R R
1 2
/ (b) R R
1 2
/
(c)( / ) R R
1 2
2
(d)( / ) R R
2 1
2
14. A large number of particles are placed
around the origin, each at a distance R from
the origin. The distance of the center of mass
of the system from the origin is
(a) equal to R
(b) less than equal to R
(c) greater then R
(d) greater than equal to R
15. A straight conductor 0.1 m long moves in a
uniform magnetic field 0.1T. The velocity of
the conductor is 15 m/s and is directed
perpendicular to the field. The emf induced
between the two ends of the conductor is
(a) 0.10 V (b) 0.15 V (c) 1.50 V (d) 15.00 V
16. A ray of light is incident at an angle i on a
glass slab of refractive index m. The angle
between reflected and refracted light is90°.
Then, the relationship betweeni andm is
(a) i =
æ
è
ç
ö
ø
÷
-
tan
1
1
m
(b) tani =m
(c)sini =m (d)cos i =m
17. Two particles A and B are moving as shown
in the figure.
Their total angular momentum about the
pointO is
(a) 9.8 kg m / s
2
(b) zero
(c) 52.7 kg m /s
2
(d) 37.9 kg m /s
2
18. A 20 cm long capillary tube is dipped
vertically in water and the liquid rises upto
10 cm. If the entire system is kept is a freely
falling platform, the length of the water
column in the tube will be
(a) 5 cm (b) 10 cm (c) 15 cm (d) 20 cm
19. A train is moving with a uniform speed of
33 m/s and an observer is approaching the
train with the same speed. If the train blows
a whistle of frequency 1000 Hz and the
velocity of sound is 333 m/s, then the
apparent frequency of the sound that the
observer hears is
(a) 1220 Hz (b) 1099 Hz (c) 1110 Hz (d) 1200 Hz
20. A photon of wavelength 300 nm interacts
with a stationary hydrogen atom in ground
state. During the interaction, whole energy of
the photon is transferred to the electron of
the atom. State which possibility is correct.
(Consider, Plank constant = ´
-
4 10
15
eVs ,
velocity of light = ´ 3 10
8
m/s, ionisation
energy of hydrogen=13.6eV)
50 O
100 O
150 O
+
–
10 V
2.2 m/s 6.5 kg
1.5 m
2.8 m 3.1 kg
3.6 m/s
A
B
O
Page 2 of 38
(a) Electron will be knocked out of the atom
(b) Electron will go to any excited state of the atom
(c) Electron will go only to first excited state of the
atom
(d) Electron will keep orbiting in the ground state of
the atom
21. ParticleA moves alongX-axis with a uniform
velocity of magnitude 10 m/s. Particle B
moves with uniform velocity 20 m/s along a
direction making an angle of 60° with the
positive direction of X-axis as shown in the
figure. The relative velocity ofB with respect
to that ofA is
(a) 10 m/s along X-axis
(b)10 3m/s along Y-axis (perpendicular to X-axis)
(c)10 5m/s along the bisection of the velocities of
A and B
(d) 30 m/s along negative X-axis
22. When light is refracted from a surface, which
of its following physical parameters does not
change?
(a) Velocity
(b) Amplitude
(c) Frequency
(d) Wavelength
23. A solid maintained at t°
1
C is kept in an
evacuated chamber at temperature t°
2
C
( ) t t
2 1
>> . The rate of heat absorbed by the
body is proportional to
(a)t t
2
4
1
4
-
(b)( ) ( ) t t
2
4
1
4
273 273 + - +
(c)t t
2 1
-
(d)t t
2
2
1
2
-
24. Block B lying on a table weighs W. The
coefficient of static friction between the
block and the table ism. Assume that the cord
between B and the knot is horizontal. The
maximum weight of the block A for which
the system will be stationary is
(a)
W tanq
m
(b)m q W tan
(c)m q W 1
2
+ tan (d)m q W sin
25. The inputs to the digital circuit are as shown
below. The outputY is
(a) A B C + +
(b)( ) A B C +
(c) A B C + +
(d) A B C + +
26. Two particles A and B having different
masses are projected from a tower with same
speed. A is projected vertically upward and
B vertically downward. On reaching the
ground
(a) velocity of A is greater than that of B
(b) velocity ofB is greater than that of A
(c) both A and B attain the same velocity
(d) the particle with the larger mass attains higher
velocity
27. The work function of metals is in the range of
2eV to 5eV. Find which of the following
wavelength of light cannot be used for
photoelectric effect? (Consider, Plank
constant = ´
-
4 10
15
eVs, velocity of light
= ´ 3 10
8
m/s)
(a) 510 nm (b) 650 nm
(c) 400 nm (d) 570 nm
28. A thin plastic sheet of refractive index 1.6 is
used to cover one of the slits of a double slit
arrangement. The central point on the screen
is now occupied by what would have been the
7th bright fringe before the plastic was used. If
the wavelength of light is 600 nm, what is the
thickness (inmm) of the plastic sheet?
(a) 7 (b) 4
(c) 8 (d) 6
60°
20 m/s
A 10 m/s
B
X
B
A
Knot
?
A
B
C
Y
Page 3 of 38
29. The length of an open organ pipe is twice the
length of another closed organ pipe. The
fundamental frequency of the open pipe is
100 Hz. The frequency of the third harmonic
of the closed pipe is
(a) 100 Hz (b) 200 Hz
(c) 300 Hz (d) 150 Hz
30. A5mF capacitor is connected in series with a
10mF capacitor. When a 300 V potential
difference is applied across this
combination, the total energy stored in the
capacitors is
(a) 15 J (b) 1.5 J
(c) 0.15 J (d) 0.10 J
31. A cylinder of height h is filled with water
and is kept on a block of height h/2. The
level of water in the cylinder is kept
constant. Four holes numbered 1, 2, 3 and 4
are at the side of the cylinder and at heights
0 4 , / h ,h/2 and3 4 h/ , respectively. When all
four holes are opened together, the hole from
which water will reach farthest distance on
the planePQ is the hole number.
(a) 1 (b) 2
(c) 3 (d) 4
32. The pressurep, volumeV and temperatureT
for a certain gas are related byp
AT BT
V
=
-
2
,
whereA andB are constants. The work done
by the gas when the temperature changes
from T
1
to T
2
while the pressure remains
constant, is given by
(a) A T T B T T ( ) ( )
2 1 2
2
1
2
- + -
(b)
A T T
V V
B T T
V V
( ) ( )
2 1
2 1
2
2
1
2
2 1
-
-
-
-
-
(c) A T T
B
T T ( ) ( )
2 1 2
2
1
2
2
- - -
(d)
A T T
V V
( )
2 1
2
2 1
-
-
33. In the circuit shown below, the switch is
kept in positiona for a long time and is then
thrown to position b. The amplitude of the
resulting oscillating current is given by
(a) E L C / (b) E R / (c) infinity (d) E C L /
34. A chargeq is placed at one corner of a cube.
The electric flux through any of the three
faces adjacent to the charge is zero. The flux
through any one of the other three faces is
(a)q/3
0
Î (b)q/6
0
Î (c)q/12
0
Î (d)q/24
0
Î
35. Two cells A and B of emf 2V and 1.5 V
respectively, are connected as shown in
figure through an external resistance 10 W.
The internal resistance of each cell is 5W.
The potential difference E
A
and E
B
across
the terminals of the cells A and B
respectively are
(a) E E
A B
= = 2.0 1.5 V V ,
(b) E
A
=2.125V, E
B
=1.375V
(c) E
A
=1.875V, E
B
=1.625V
(d) E
A
=1.875V, E
B
=1.375 V
36. Two charges +q and -q are placed at a
distance a in a uniform electric field. The
dipole moment of the combination is
2qa(cos
$
sin
$
) q q i j + , where, q is the angle
between the direction of the field and the
line joining the two charges.
Which of the following statement(s) is/are
correct?
(a) The torque exerted by the field on the dipole
vanishes
(b) The net force on the dipole vanishes
(c) The torque is independent of the choice of
coordinates
(d) The net force is independent of a
h
h/2
1
2
3
4
P Q
a
b
Switch
C
R E
L
A
B
2V, 5O
1.5V
5O
10 O
Page 4 of 38
Page 5


Physics
1. Two particles of massm
1
andm
2
; approach
each other due to their mutual gravitational
attraction only. Then,
(a) accelerations of both the particles are equal
(b) acceleration of the particle of mass m
1
is
proportional tom
1
(c) acceleration of the particle of mass m
1
is
proportional tom
2
(d) acceleration of the particle of massm
1
is inversely
proportional tom
1
2. Three bodies of the same material and
having masses m m , and 3m are at
temperatures 40°C, 50°C and 60°C,
respectively. If the bodies are brought in
thermal contact, the final temperature
will be
(a) 45°C (b) 54°C
(c) 52°C (d) 48°C
3. A satellite has kinetic energy K, potential
energy V and total energy E. Which of the
following statements is true?
(a) K V = - /2 (b) K V = /2
(c) E K = /2 (d) E K = - /2
4. An object is located 4 m from the first of two
thin converging lenses of focal lengths 2 m
and 1 m, respectively. The lenses are
separated by 3 m. The final image formed by
the second lens is located from the source at
a distance of
(a) 8.0 m (b) 5.5 m
(c) 6.0 m (d) 6.5 m
5. A simple pendulum of length L swings in a
vertical plane. The tension of the string
when it makes an angle q with the vertical
and the bob of massm moves with a speedv
is (g is the gravitational acceleration)
(a) mv L
2
/ (b) mg mv L cos / q +
2
(c) mg mv L cos / q -
2
(d) mg cos q
6. The length of a metal wire is L
1
when the
tension is T
1
and L
2
when the tension is T
2
.
The unstretched length of wire is
(a)
L L
1 2
2
+
(b) LL
1 2
(c)
T L TL
T T
2 1 1 2
2 1
-
-
(d)
T L TL
T T
2 1 1 2
2 1
+
+
7. The line AA¢ is on charged infinite
conducting plane which is
perpendicular to the plane of the
paper. The plane has a surface
density of charges and B is ball of
mass m with a like charge of
magnitudeq.B is connected by string from a
point on the lineAA¢. The tangent of angle( ) q
formed between the lineAA¢ and the string is
(a)
q
mg
s
2
0
Î
(b)
q
mg
s
pe
0
4
(c)
q
mg
s
pe 2
0
(d)
q
mg
s
e
0
8. The currentI is in the circuit shown is
(a) 1.33 A (b) zero (c) 2.00 A (d) 1.00 A
3m 4m
Source
?
A
B
A'
2V
2O 2O
2V
2O
2V
–
+
–
+
–
+
I
WB JEE
Engineering Entrance Exam
Solved Paper 2015
Page 1 of 38
9. A hollow sphere of external radius R and
thickness t R ( ) << is made of a metal of
densityr. The sphere will float in water, if
(a)t
R
£
r
(b)t
R
£
3r
(c)t
R
£
2r
(d)t
R
³
3r
10. A metal wire of circular cross-section has a
resistance R
1
. The wire is now stretched
without breaking, so that its length is doubled
and the density is assumed to remain the
same. If the resistance of the wire now
becomesR
2
, thenR R
2 1
: is
(a) 1 : 1 (b) 1 : 2 (c) 4 : 1 (d) 1 : 4
11. Assume that each diode as shown in the
figure has a forward bias resistance of50 W
and an infinite reverse bias resistance. The
current through the resistance150 W is
(a) 0.66 A (b) 0.05 A (c) zero (d) 0.04 A
12. The rms speed of oxygen is v at a particular
temperature. If the temperature is doubled
and oxygen molecules dissociate into
oxygen atoms, the rms speed becomes
(a) v (b) 2v
(c)2v (d) 4v
13. Two particles, A and B, having equal
charges, after being accelerated through the
same potential difference enter into a region
of uniform magnetic field and the particles
describe circular paths of radii R
1
and R
2
,
respectively. The ratio of the masses ofA and
B is
(a) R R
1 2
/ (b) R R
1 2
/
(c)( / ) R R
1 2
2
(d)( / ) R R
2 1
2
14. A large number of particles are placed
around the origin, each at a distance R from
the origin. The distance of the center of mass
of the system from the origin is
(a) equal to R
(b) less than equal to R
(c) greater then R
(d) greater than equal to R
15. A straight conductor 0.1 m long moves in a
uniform magnetic field 0.1T. The velocity of
the conductor is 15 m/s and is directed
perpendicular to the field. The emf induced
between the two ends of the conductor is
(a) 0.10 V (b) 0.15 V (c) 1.50 V (d) 15.00 V
16. A ray of light is incident at an angle i on a
glass slab of refractive index m. The angle
between reflected and refracted light is90°.
Then, the relationship betweeni andm is
(a) i =
æ
è
ç
ö
ø
÷
-
tan
1
1
m
(b) tani =m
(c)sini =m (d)cos i =m
17. Two particles A and B are moving as shown
in the figure.
Their total angular momentum about the
pointO is
(a) 9.8 kg m / s
2
(b) zero
(c) 52.7 kg m /s
2
(d) 37.9 kg m /s
2
18. A 20 cm long capillary tube is dipped
vertically in water and the liquid rises upto
10 cm. If the entire system is kept is a freely
falling platform, the length of the water
column in the tube will be
(a) 5 cm (b) 10 cm (c) 15 cm (d) 20 cm
19. A train is moving with a uniform speed of
33 m/s and an observer is approaching the
train with the same speed. If the train blows
a whistle of frequency 1000 Hz and the
velocity of sound is 333 m/s, then the
apparent frequency of the sound that the
observer hears is
(a) 1220 Hz (b) 1099 Hz (c) 1110 Hz (d) 1200 Hz
20. A photon of wavelength 300 nm interacts
with a stationary hydrogen atom in ground
state. During the interaction, whole energy of
the photon is transferred to the electron of
the atom. State which possibility is correct.
(Consider, Plank constant = ´
-
4 10
15
eVs ,
velocity of light = ´ 3 10
8
m/s, ionisation
energy of hydrogen=13.6eV)
50 O
100 O
150 O
+
–
10 V
2.2 m/s 6.5 kg
1.5 m
2.8 m 3.1 kg
3.6 m/s
A
B
O
Page 2 of 38
(a) Electron will be knocked out of the atom
(b) Electron will go to any excited state of the atom
(c) Electron will go only to first excited state of the
atom
(d) Electron will keep orbiting in the ground state of
the atom
21. ParticleA moves alongX-axis with a uniform
velocity of magnitude 10 m/s. Particle B
moves with uniform velocity 20 m/s along a
direction making an angle of 60° with the
positive direction of X-axis as shown in the
figure. The relative velocity ofB with respect
to that ofA is
(a) 10 m/s along X-axis
(b)10 3m/s along Y-axis (perpendicular to X-axis)
(c)10 5m/s along the bisection of the velocities of
A and B
(d) 30 m/s along negative X-axis
22. When light is refracted from a surface, which
of its following physical parameters does not
change?
(a) Velocity
(b) Amplitude
(c) Frequency
(d) Wavelength
23. A solid maintained at t°
1
C is kept in an
evacuated chamber at temperature t°
2
C
( ) t t
2 1
>> . The rate of heat absorbed by the
body is proportional to
(a)t t
2
4
1
4
-
(b)( ) ( ) t t
2
4
1
4
273 273 + - +
(c)t t
2 1
-
(d)t t
2
2
1
2
-
24. Block B lying on a table weighs W. The
coefficient of static friction between the
block and the table ism. Assume that the cord
between B and the knot is horizontal. The
maximum weight of the block A for which
the system will be stationary is
(a)
W tanq
m
(b)m q W tan
(c)m q W 1
2
+ tan (d)m q W sin
25. The inputs to the digital circuit are as shown
below. The outputY is
(a) A B C + +
(b)( ) A B C +
(c) A B C + +
(d) A B C + +
26. Two particles A and B having different
masses are projected from a tower with same
speed. A is projected vertically upward and
B vertically downward. On reaching the
ground
(a) velocity of A is greater than that of B
(b) velocity ofB is greater than that of A
(c) both A and B attain the same velocity
(d) the particle with the larger mass attains higher
velocity
27. The work function of metals is in the range of
2eV to 5eV. Find which of the following
wavelength of light cannot be used for
photoelectric effect? (Consider, Plank
constant = ´
-
4 10
15
eVs, velocity of light
= ´ 3 10
8
m/s)
(a) 510 nm (b) 650 nm
(c) 400 nm (d) 570 nm
28. A thin plastic sheet of refractive index 1.6 is
used to cover one of the slits of a double slit
arrangement. The central point on the screen
is now occupied by what would have been the
7th bright fringe before the plastic was used. If
the wavelength of light is 600 nm, what is the
thickness (inmm) of the plastic sheet?
(a) 7 (b) 4
(c) 8 (d) 6
60°
20 m/s
A 10 m/s
B
X
B
A
Knot
?
A
B
C
Y
Page 3 of 38
29. The length of an open organ pipe is twice the
length of another closed organ pipe. The
fundamental frequency of the open pipe is
100 Hz. The frequency of the third harmonic
of the closed pipe is
(a) 100 Hz (b) 200 Hz
(c) 300 Hz (d) 150 Hz
30. A5mF capacitor is connected in series with a
10mF capacitor. When a 300 V potential
difference is applied across this
combination, the total energy stored in the
capacitors is
(a) 15 J (b) 1.5 J
(c) 0.15 J (d) 0.10 J
31. A cylinder of height h is filled with water
and is kept on a block of height h/2. The
level of water in the cylinder is kept
constant. Four holes numbered 1, 2, 3 and 4
are at the side of the cylinder and at heights
0 4 , / h ,h/2 and3 4 h/ , respectively. When all
four holes are opened together, the hole from
which water will reach farthest distance on
the planePQ is the hole number.
(a) 1 (b) 2
(c) 3 (d) 4
32. The pressurep, volumeV and temperatureT
for a certain gas are related byp
AT BT
V
=
-
2
,
whereA andB are constants. The work done
by the gas when the temperature changes
from T
1
to T
2
while the pressure remains
constant, is given by
(a) A T T B T T ( ) ( )
2 1 2
2
1
2
- + -
(b)
A T T
V V
B T T
V V
( ) ( )
2 1
2 1
2
2
1
2
2 1
-
-
-
-
-
(c) A T T
B
T T ( ) ( )
2 1 2
2
1
2
2
- - -
(d)
A T T
V V
( )
2 1
2
2 1
-
-
33. In the circuit shown below, the switch is
kept in positiona for a long time and is then
thrown to position b. The amplitude of the
resulting oscillating current is given by
(a) E L C / (b) E R / (c) infinity (d) E C L /
34. A chargeq is placed at one corner of a cube.
The electric flux through any of the three
faces adjacent to the charge is zero. The flux
through any one of the other three faces is
(a)q/3
0
Î (b)q/6
0
Î (c)q/12
0
Î (d)q/24
0
Î
35. Two cells A and B of emf 2V and 1.5 V
respectively, are connected as shown in
figure through an external resistance 10 W.
The internal resistance of each cell is 5W.
The potential difference E
A
and E
B
across
the terminals of the cells A and B
respectively are
(a) E E
A B
= = 2.0 1.5 V V ,
(b) E
A
=2.125V, E
B
=1.375V
(c) E
A
=1.875V, E
B
=1.625V
(d) E
A
=1.875V, E
B
=1.375 V
36. Two charges +q and -q are placed at a
distance a in a uniform electric field. The
dipole moment of the combination is
2qa(cos
$
sin
$
) q q i j + , where, q is the angle
between the direction of the field and the
line joining the two charges.
Which of the following statement(s) is/are
correct?
(a) The torque exerted by the field on the dipole
vanishes
(b) The net force on the dipole vanishes
(c) The torque is independent of the choice of
coordinates
(d) The net force is independent of a
h
h/2
1
2
3
4
P Q
a
b
Switch
C
R E
L
A
B
2V, 5O
1.5V
5O
10 O
Page 4 of 38
37. Find the right condition(s) for Fraunhoffer
diffraction due to a single slit.
(a) Source is at infinite distance and the incident
beam has converged at the slit
(b) Source is near to the slit and the incident beam is
parallel
(c) Source is at infinity and the incident beam is parallel
(d) Source is near to the slit and the incident beam
has converged at the slit
38. The conducting loop in the form of a circle is
placed in a uniform magnetic field with its
plane perpendicular to the direction of the
field. An emf will be induced in the loop, if
(a) it is translated parallel to itself
(b) it is rotated about one of its diameters
(c) it is rotated about its own axis which is parallel to
the field
(d) the loop is deformed from the original shape
39. A circular disc rolls on a horizontal floor
without slipping and the centre of the disc
moves with a uniform velocity v. Which of
the following values of the velocity at a point
on the rim of the disc can have?
(a) v
(b) - v
(c) 3v
(d) Zero
40. Consider two particles of different masses. In
which of the following situations the heavier
of the two particles will have smaller
de-Broglie wavelength?
(a) Both have a free fall through the same height
(b) Both move with the same kinetic energy
(c) Both move with the same linear momentum
(d) Both move with the same speed
Chemistry
41. Match the flame colours of the alkaline earth
metal salts in the Bunsen burner.
A. Calcium p. Brick red
B. Strontium q. Apple green
C. Barium r. Crimson
A B C
(a) p r q
(b) r p q
(c) q r p
(d) p q r
42. Extraction of gold (Au) involves the
formation of complex ionsX andY.
Gold ore ¾¾¾¾® + ¾® +
-
-
CN , H O, O
Roasting Zn
2 2
HO Au X Y
X andY respectively are
(a) Au(CN)
2
-
and Zn(CN)
4
2-
(b) Au(CN)
4
3-
and Zn(CN)
4
2-
(c) Au(CN)
3
-
and Zn(CN)
6
4-
(d) Au(CN)
4
-
and Zn(CN)
3
-
43. The atomic number of cerium (Ce) is 58. The
correct electronic configuration ofCe
3+
ion is
(a)[Xe]4
1
f (b)[Kr]4
1
f
(c)[Xe]4
13
f (d)[Kr]4
1
d
44.
The major product of the above reaction is
45.
The product of the above reaction is
H C
2
CH
3
CH
2
HBr (1 equiv.)
Br
CH
3
CH
3
H C
3
CH
3
Br
H C
3
Br
CH
2
H C
3
H C
3
H C
3
Br
(a)
(c)
(b)
(d)
Cl
Br
NH
3
EtOH
???
Page 5 of 38