Page 1 of 5
1
CODE - PP
1. An em wave is propagating in a medium with a
velocity
V Vi ˆ . The instantaneous oscillating
electric field of this em wave is along +y axis. Then
the direction of oscillating magnetic field of the em
wave will be along :-
(1) –z direction
(2) +z direction
(3) –y direction
(4) –x direction
Ans. (2)
2. The refractive index of the material of a prism is
2 and the angle of the prism is 30°. One of the
two refracting surfaces of the prism is made a mirror
inwards, by silver coating. A beam of
monochromatic light entering the prism from the
other face will retrace its path (after reflection from
the silvered surface) if its angle of incidence on the
prism is :-
(1) 60° (2) 45° (3) 30° (4) zero
Ans. (2)
3. The magnetic potential energy stored in a certain
inductor is 25 mJ, when the current in the inductor
is 60 mA. This inductor is of inductance :-
(1) 0.138 H (2) 138.88 H
(3) 1.389 H (4) 13.89 H
Ans. (4)
4. An object is placed at a distance of 40 cm from a
concave mirror of focal length 15 cm. If the object
is displaced through a distance of 20 cm towards
the mirror, the displacement of the image will be:-
(1) 30 cm away from the mirror
(2) 36 cm away from the mirror
(3) 30 cm towards the mirror
(4) 36 cm towards the mirror
Ans. (2)
5. In the combination of the following gates the output
Y can be written in terms of inputs A and B as :-
Y
A
B
(1) A . B (2) A . B A . B
(3) A . B A.B (4) A B
Ans. (2)
NEET(UG)–2018 TEST PAPER WITH ANSWER
(HELD ON SUNDAY 06th MAY, 2018)
6. In the circuit shown in the figure, the input voltage
Vi
is 20 V, VBE = 0 and VCE = 0. The values of IB,
IC and are given by :-
Vi
RB
B
C
E
20V
500k
RC 4 k
(1) IB = 40 A, IC = 10 mA, = 250
(2) IB = 25 A, IC = 5 mA, = 200
(3) IB = 20 A, IC = 5 mA, = 250
(4) IB = 40 A, IC = 5 mA, = 125
Ans. (4)
7. In a p-n junction diode, change in temperature due
to heating :-
(1) affects only reverse resistance
(2) affects only forward resistance
(3) does not affect resistance of p-n junction
(4) affects the overall V – I characteristics of
p-n junction
Ans. (4)
8. A small sphere of radius 'r' falls from rest in a viscous
liquid. As a result, heat is produced due to viscous
force. The rate of production of heat when the
sphere attains its terminal velocity, is proportional
to :-
(1) r3 (2) r2
(3) r5 (4) r4
Ans. (3)
9. A sample of 0.1 g of water at 100o
C and normal
pressure (1.013 105 Nm–2) requires 54 cal of
heat energy to convert to steam at 100o
C. If the
volume of the steam produced is 167.1 cc, the
change in internal energy of the sample, is :-
(1) 104.3 J (2) 208.7 J
(3) 42.2 J (4) 84.5 J
Ans. (2)
10. Two wires are made of the same material and have
the same volume. The first wire has cross-sectional
area A and the second wire has cross-sectional area
3A. If the length of the first wire is increased by l
on applying a force F, how much force is needed
to stretch the second wire by the same amount ?
(1) 9F (2) 6F (3) 4F (4) F
Ans. (1)
PHYSICS
If you have any query then message us on Entrance Mantra's facebook page. Search Entrance Mantra on google and facebook
यदिआपकेमनमेंकोईप्रश्न हैतो हमेंEntrance Mantra केFacebook पेज परसंदेशभेजें। गूगल और फेसबुकपरEntrance Mantra खोजें
Page 2 of 5
2
NEET(UG)-2018
11. The power radiated by a black body is P and it
radiates maximum energy at wavelength 0. If the
temperature of the black body is now changed so
that it radiates maximum energy at wavelength
0
3
4 , the power radiated by it becomes nP. The
value of n is :-
(1) 3
4 (2) 4
3
(3) 256
81 (4) 81
256
Ans. (3)
12. A set of 'n' equal resistors, of value 'R' each, are
connected in series to a battery of emf 'E' and
internal resistance 'R'. The current drawn is I. Now,
the 'n' resistors are connected in parallel to the same
battery. Then the current drawn from battery
becomes 10 I. The value of 'n' is :-
(1) 10 (2) 11
(3) 20 (4) 9
Ans. (1)
13. A battery consists of a variable number 'n' of identical
cells (having internal resistance 'r' each) which are
connected in series. The terminals of the battery are
short-circuited and the current I is measured. Which
of the graphs shows the correct relationship between
I and n ?
(1)
I
O n
(2)
I
O n
(3)
O n
I
(4)
I
O n
Ans. (1)
14. A carbon resistor (47 4.7) k is to be marked with
rings of different colours for its identification. The
colour code sequence will be :-
(1) Violet – Yellow – Orange – Silver
(2) Yellow – Violet – Orange – Silver
(3) Yellow – Green – Violet – Gold
(4) Green – Orange – Violet – Gold
Ans. (2)
15. Which one of the following statements is
incorrect ?
(1) Rolling friction is smaller than sliding friction
(2) Limiting value of static friction is directly
proportional to normal reactions
(3) Frictional force opposes the relative motion
(4) Coefficient of sliding friction has dimensions of
length
Ans. (4)
16. A moving block having mass m, collides with another
stationary block having mass 4m. The lighter block
comes to rest after collision. When the initial velocity
of the lighter block is v, then the value of coefficient
of resistitution (e) will be :-
(1) 0.5 (2) 0.25
(3) 0.8 (4) 0.4
Ans. (2)
17. A body initially at rest and sliding along a frictionless
track from a height h (as shown in the figure) just
completes a vertical circle of diameter AB = D. The
height h is equal to :-
B
A
h
(1) 3 D
2 (2) D
(3) 7 D
5 (4) 5 D
4
Ans. (4)
18. Three objects, A : (a solid sphere), B : (a thin circular
disk) and C = (a circular ring), each have the same
mass M and radius R. They all spin with the same
angular speed about their own symmetry axes.
The amounts of work (W) required to bring them to
rest, would satisfy the relation :-
(1) WC > WB > WA
(2) WA > WB > WC
(3) WB > WA > WC
(4) WA > WC > WB
Ans. (1)
Page 3 of 5
3
CODE - PP
19. A tuning fork is used to produce resonance in a glass
tube. The length of the air column in this tube can
be adjusted by a variable piston. At room
temperature of 27°C two successiv resonances are
produced at 20 cm and 73 cm column length. If
the frequency of the tuning fork is 320 Hz, the
velocity of sound in air at 27°C is :-
(1) 330 m/s (2) 339 m/s
(3) 350 m/s (4) 300 m/s
Ans. (2)
20. An electron falls from rest through a vertical
distance h in a uniform and vertically upward directed
electric field E. The direction of electrical field is now
reversed, keeping its magnitude the same. A proton
is allowed to fall from rest in through the same vertical
distance h. The time fall of the electron, in
comparison to the time fall of the proton is :-
(1) smaller (2) 5 times greater
(3) 10 times greater (4) equal
Ans. (1)
21. A pendulum is hung from the roof of a sufficiently
high building and is moving freely to and fro like a
simple harmonic oscillator. The acceleration of the
bob of the pendulum is 20 m/s2 at a distance of
5 m from the mean position. The time period of
oscillation is :-
(1) 2 s (2) s
(3) 2 s (4) 1 s
Ans. (2)
22. The electrostatic force between the metal plates of
an isolated parallel plate capacitor C having a
charge Q and area A, is :-
(1) independent of the distance between the plates.
(2) linearly proportional to the distance between the
plates
(3) proportional to the square root of the distance
between the plates.
(4) inversely proportional to the distance between
the plates.
Ans. (1)
23. An electron of mass m with an initial velocity
0 0 V V i(V 0) ˆ enters an electric field
0 E E iˆ
(E0 = constant >0) at t = 0. If 0 is its de-Broglie
wavelength initially, then its de-Broglie wavelength
at time t is :-
(1)
0
0
0
eE 1 t
mV
(2)
0
0
0
eE 1 t
mV
(3) 0t
(4) 0
Ans. (1)
24. For a radioactive material, half-life is 10 minutes.
If initially there are 600 number of nuclei, the time
taken (in minutes) for the disintegration of 450 nuclei
is :-
(1) 20 (2) 10
(3) 30 (4) 15
Ans. (1)
25. When the light of frequency 20 (where 0 is
threshold frequency), is incident on a metal plate,
the maximum velocity of electrons emitted is v1.
When the frequency of the incident radiation is
increased to 50, the maximum velocity of electrons
emitted from the same plate is v2. The ratio of v1
to v2 is :-
(1) 1 : 2 (2) 1 : 4
(3) 4 : 1 (4) 2 : 1
Ans. (1)
26. the ratio of kinetic energy to the total energy of an
electron in a Bohr orbit of the hydrogen atom, is :-
(1) 1 : 1 (2) 1 : –1
(3) 2 : –1 (4) 1 : –2
Ans. (2)
27. The moment of the force,
ˆ ˆ ˆ F 4i 5j 6k at
(2, 0, –3), about the point (2, –2, –2), is given by :-
(1) ˆ ˆ ˆ 8i 4j 7k
(2) ˆ ˆ ˆ 4i j 8k
(3) ˆ ˆ ˆ 7i 8j 4k
(4) ˆ ˆ ˆ 7i 4j 8k
Ans. (4)