Practice problems on NEET, NEET 2016

Question 1

From a disc of radius R and mass M, a circular hole of diameter R, whose rim passes through the center is cut. What is the moment of inertia of the remaining part of the disc about a perpendicular axis, passing through the center?

Accepted Answer

3213MR2​

Answer

3215MR2​

Answer

3211MR2​

Answer

329MR2​

Question 2

A square loop A B C D carrying a current i, is placed near and co planar with a long straight conductor X Y carrying a current I, the net force on the loop will be:

Accepted Answer

3π2μ0​Ii​

Answer

2πμ0​Ii​

Answer

2pi2μ0​IiL​

Answer

2piμ0​IiL​

Question 3

The magnetic susceptibility is negative for:

Accepted Answer

diamagnetic material only

Answer

paramagnetic material only

Answer

ferromagnetic material only

Answer

paramagnetic and ferromagnetic materials

Question 4

A siren emitting a sound of frequency 800 Hz moves away from an observer towards a cliff at a speed of 15 ms−1. Then, the frequency of sound that the observer hears in the echo reflected from the cliff is :(Take velocity of sound in air = 330 ms−1)

Accepted Answer

838 Hz

Answer

765 Hz

Answer

800 Hz

Answer

885 Hz

Question 5

A capacitor of 2μF is charged as shown in the diagram. When the switch S is turned to position 2, the percentage of its stored energy dissipated is:

Accepted Answer

80%

Answer

0%

Answer

20%

Answer

75%

Question 6

In a diffraction pattern due to a single slit of width ‘a’, the first minimum is observed at an angle 30o when light of wavelength 5000 Å is incident on the slit. The first secondary maximum is observed at an angle of :

Accepted Answer

sin−1(43​)

Answer

sin−1(41​)

Answer

sin−1(32​)

Answer

sin−1(21​)

Question 7

At what height from the surface of earth the gravitation potential and the value of g are −5.4 × 107J kg−2 and 6.0 ms−2 respectively? Take the radius of earth as 6400 km:

Accepted Answer

2600 km

Answer

1600 km

Answer

1400 km

Answer

2000 km

Question 8

Out of the following options which one can be used to produce a propagating electromagnetic wave?

Accepted Answer

An accelerating charge

Answer

A charge moving at constant velocity

Answer

A stationary charge

Answer

A charge less particle

Question 9

Two identical charged spheres suspended from a common point by two mass less strings of lengths ?, are initially at a distance d(d v. Then v varies as a function of the distance ? between the spheres, as

Accepted Answer

v∝x−21​

Answer

v∝x21​

Answer

v∝x

Answer

v∝x−1

Question 10

A uniform rope of length L and mass m1​, hangs vertically from a rigid support. A block of mass m2​ is attached to the free end of the rope. A transverse pulse of wavelength λ1​ is produced at the lower end ofthe rope. The wavelength of the pulse when it reaches the top of the rope is λ2​. The ratio λ1​λ2​​ is :

Accepted Answer

m2​m1​+m2​​​

Answer

m2​m1​​​

Answer

m1​m2​​​

Answer

m1​m1​+m2​​​

Question 11

A refrigerator works between 4ºC and 30ºC. It is required to remove 600 calories of heat every second in order to keep the temperature of the refrigerated space constant. The power required is :(Take 1 cal = 4.2 Joules)

Accepted Answer

2365 W

Answer

2.365 W

Answer

23.65 W

Answer

236.5 W

Question 12

An air column, closed at one end and open at the other, resonates with a tuning fork when the smallest length of the column is 50 cm. The next larger length of the column resonating with the same tuning fork is:

Accepted Answer

150 cm

Answer

66.7 cm

Answer

100 cm

Answer

200 cm

Question 13

Consider the junction diode as ideal. The value of current flowing through AB is :

Accepted Answer

10−2A

Answer

0 A

Answer

10−1A

Answer

10−3A

Question 14

The charge flowing through a resistance R varies with time t as Q=at−bt2  where a and b are positive constants. The total heat produced in R is :

Accepted Answer

6ba3R​

Answer

3ba3R​

Answer

2ba3R​

Answer

ba3R​

Question 15

A black body is at a temperature of 5760 K. The energy of radiation emitted by the body at wavelength 250 n m is U1​, at wavelength 500 n m is U2​ and that at 1000 n m is U3​. Wienies constant, b = 2.88 × 106 n m K. Which of the following is correct?

Accepted Answer

U1​>U2​

Answer

U1​=0

Answer

U3​=0

Answer

U2​>U1​

Question 16

Coefficient of linear expansion of brass and steel rods are α1​ and α2​. Lengths of brass and steel rods are l1​ and l2​ respectively. If (l2​−l1​) is maintained same at all temperatures, which one of the following relations holds good?

Accepted Answer

α1​l1​=α2​l2​

Answer

α12​l2​=α22​l1​

Answer

α1​l22​=α2​l12​

Answer

α12​l2​=α22​l1​

Question 17

A npn transistor is connected in common emitter configuration in a given amplifier. A load resistance of 800 Ω is connected in the collector circuit and the voltage drop across it is 0.8 V. If the current amplification factor is 0.96 and the input resistance of the circuit is 192 Ω, the voltage gain and the power gain of the amplifier will respectively be :

Accepted Answer

4, 3.84

Answer

3.69, 3.84

Answer

4, 4

Answer

4, 3.69

Question 18

The intensity at the maximum in a Young’s double slit experiment is I0​. Distance between two slits is d = 5λ, where λ is the wavelength of light used in the experiment. What will be the intensity in front of one of the slits on the screen placed at a distance D = 10 d?

Accepted Answer

2I0​​

Answer

I0​

Answer

4I0​​

Answer

43​I0​

Question 19

A uniform circular disc of radius 50 cm at rest is free to tum about an axis which is perpendicular to its plane and passes through its center. It is subjected to a torque which produces a constant angular acceleration of 2.0 rad s−2. Its net acceleration in ms−2 at the end of 2.0 s is approximately:

Accepted Answer

8.0

Answer

7.0

Answer

6.0

Answer

3.0

Question 20

An electron of mass m and a photon have same energy E. the ratio of de-Imbroglio wavelengths associated with them is:SS

Accepted Answer

e1​(2mE​)21​

Answer

(2mE​)21​

Answer

c(2mE)21​

Answer

e1​(E2m​)21​