NEET-UG 2025 · Code 45

A microscope has an objective of focal length 2 cm, eyepiece of focal length 4 cm and the tube length of 40 cm. If the distance of distinct vision of eye is 25 cm, the magnification in the microscope is

1. A100
2. B125
3. C150
4. D250

An electron (mass 9×10⁻³¹ kg and charge 1.6×10⁻¹⁹C) moving with speed c/100 (c = speed of light) is injected into a magnetic field B⃗ of magnitude 9×10⁻⁴ T perpendicular to its direction of motion. We wish to apply an uniform electric field E⃗ together with the magnetic field so that the electron does not deflect from its path. Then (speed of light c = 3×10⁸ ms⁻¹)

1. AE⃗ is perpendicular to B⃗ and its magnitude is 27×10⁴ V m⁻¹
2. BE⃗ is perpendicular to B⃗ and its magnitude is 27×10² V m⁻¹
3. CE⃗ is parallel to B⃗ and its magnitude is 27×10² V m⁻¹
4. DE⃗ is parallel to B⃗ and its magnitude is 27×10⁴ V m⁻¹

There are two inclined surfaces of equal length (L) and same angle of inclination 45° with the horizontal. One of them is rough and the other is perfectly smooth. A given body takes 2 times as much time to slide down on rough surface than on the smooth surface. The coefficient of kinetic friction (μₖ) between the object and the rough surface is close to

1. A0.25
2. B0.40
3. C0.5
4. D0.75

The kinetic energies of two similar cars A and B are 100 J and 225 J respectively. On applying breaks, car A stops after 1000 m and car B stops after 1500 m. If F_A and F_B are the forces applied by the breaks on cars A and B, respectively, then the ratio F_A/F_B is

1. A3/2
2. B2/3
3. C1/3
4. D1/2

The electric field in a plane electromagnetic wave is given by E_z = 60 cos (5x + 1.5×10⁹ t) V/m. Then expression for the corresponding magnetic field is (here subscripts denote the direction of the field) :

1. AB_y = 2×10⁻⁷ cos (5x + 1.5×10⁹ t) T
2. BB_x = 2×10⁻⁷ cos (5x + 1.5×10⁹ t) T
3. CB_z = 60 cos (5x + 1.5×10⁹ t) T
4. DB_y = 60 sin (5x + 1.5×10⁹ t) T

A ball of mass 0.5 kg is dropped from a height of 40 m. The ball hits the ground and rises to a height of 10 m. The impulse imparted to the ball during its collision with the ground is (Take g = 9.8 m/s²)

1. A21 NS
2. B7 NS
3. C0
4. D84 NS

A 2 amp current is flowing through two different small circular copper coils having radii ratio 1:2. The ratio of their respective magnetic moments will be

1. A1:4
2. B1:2
3. C2:1
4. D4:1

In a certain camera, a combination of four similar thin convex lenses are arranged axially in contact. Then the power of the combination and the total magnification in comparison to the power (p) and magnification (m) for each lens will be, respectively –

1. A4p and 4m
2. Bp⁴ and 4m
3. C4p and m⁴
4. Dp⁴ and m⁴