NEET WEEKLY TEST PHYSICS (18.10.2025)

1. The test is of 90 minutes duration and Test Booklet contains 45 questions. Each question carried 4 marks for each correct response, the candidate will get 4 marks. For each incorrect response, one mark will be deducted from the total scores. The maximum marks are 180.

2. Use of Cell phone/Electronics gadgets/Calculator etc. are not allowed.

PHYSICS

1. An electron of mass m and charge q is travelling with a speed v along a circular path of radius r at right angles to a uniform of magnetic field B. If speed of the electron is doubled, then resulting path would have a radius of

1) r/4
2) r/2
3) 2r
4) 4r

2. An electron (mass = 9.0×10⁻³¹ kg and charge = 1.6×10⁻¹⁹ C) is moving in a circular orbit in a magnetic field of 1.0×10⁻⁴ Wb/m². What is its period of revolution?

3. A beam of electrons passes undeflected through mutually perpendicular electric and magnetic fields. If the electric field is switched off, and the same magnetic field is maintained, the electrons move:

1) in a circular orbit
2) along a parabolic path
3) along a straight line
4) in an elliptical orbit.

4. Under the influence of a uniform magnetic field, a charged particle is moving in a circle of radius R with constant speed v. The time period of the motion

1) depends on both R and v
2) is independent of both R and v
3) depends on R and not on v
4) depends on v and not on R

5. Three identical charge particles A, B and C are projected are projected to the uniform magnetic field with velocity v₁, v₂ and v₃ (v₁<v₂<v₃), respectively such that T₁, T₂ and T₃ are their respective time period of revolution and r₁, r₂ and r₃ are respective radii of circular path described. Then,

6. An electron moves with a speed of 2 × 10⁵ m/s along the + x-direction in a magnetic field . The magnitude of the force (in newton) experienced by the electron is (the charge on electron = 1.6 × 10^–19 C)

1) 1.18 × 10^–13
2) 1.28 × 10^–13
3) 1.6 × 10^–13
4) 1.72 × 10^–13

7. A particle with charge +Q and mass m enters a magnetic field to magnitude B existing only of the right of the boundary YZ. The direction of the motion of the particle is perpendicular to the direction of B. Let T=2πm/qB, The time spent by the particle in the field will be

8. An electron moves in a circular orbit with a uniform speed v. It produces a magnetic field B at the centre of the circle. The radius of the circle is

9. An α particle and a proton travel with same velocity in a magnetic field perpendicular to the direction of their velocities, find the ratio of the radii of their circular path

1) 4:1
2) 1:4
3) 2:1
4) 1:2

10. There are two straight conductors, carrying currents i₁ and i₂. Both the conductors are kept parallel to each other at a separation 2d. The magnetic field is measured at a point midway between the conductors. Magnetic field intensity at the above specified point is 20 mT when both the wires carry current in the same direction but it becomes 80 mT when the current in one of them is reversed. Assume i₁ > i₂ and find i₁ /i₂.

1) 2
2) 5/3
3) 4
4) 7/3

11. Two long conductors, separated by a distance d carry current I₁ and I₂ in the same direction. They exert a force F on each other. Now, the current in one of them is increased to two times and its direction is reversed. The distance d is also increased to 3d. The new value of the force between them is

12. Quantisation of charge implies

1) Charge cannot be destroyed
2) Charge exists on particles
3) There is a minimum permissible charge on a particle
4) Charge, which is a fraction of a coulomb is not possible.

13. Two charges q and -3q are placed fixed on x–axis separated by distance Where should a third charge 2q be placed from charge q such that it will not experience any force?

1) 8 Vm
2) 12 Vm
3) 16 Vm
4) zero

15. Choose the incorrect option

1) Electric field lines do not pass through a conductor
2) Electric charges are quantized
3) Electric field lines pass through an equipotential surface
4) Electric field line is a vector quantity

16. Five-point charge each having magnitude ‘q’ are placed at the corner of hexagon as shown in the figure. Net electric at the centre ‘O’ is . To get net electric field at ‘O’ be charge placed on the remaining sixth corner should be

1) 6q
2) -6q
3) 5q
4) -5q

17. In a region, the potential is represented by V(x,y,z)=6x-4xy-2y+8yz. The electric field at point (1,0,2) is

1) 11.66 NC^-1
2) 136 NC^-1
3) 16 NC^-1
4) 6.78 NC^-1

18. A solid sphere made out of copper has radius R. If charges Q are distributed uniformly in that sphere then which of the following roughly represents the variation of the electric field (E) versus distance (r) from the center of the sphere?

19. What is the flux through a cube of side ‘a’ if a point charge q is at one of its corners?

20. If Mr. Saia moves a unit positive charge from one point to another on an equipotential surface, then

1) Work is done on the charge
2) Work is done by the charge
3) Potential energy of the charged is changed
4) No work is done on the charge

21. Two-point charges -q and +9q are kept at r = 12 cm apart as shown. The electric field vanished at:

1) 6 cm from point A toward B
2) 3 cm from point A opposite to B
3) 9 cm from point B towards A
4) 18 cm from the point B towards A

22. There are two charges 1 µC and 2 µC. The ratio of the magnitude of forces acting on them due to their interaction will be

1) 1:2
2) 2:1
3) 1:1
4) 1:4

23. The dimensional formula for magnetic field (B) is

1) [ML¹ T^-2 A¹ ]   
2) [ML⁰ T^-2 A^-1]
3) [ML¹ T^-2 A^-2]
4) [ML⁰ T² A^-1 ]

24. The relative error in measuring the surface area of a sphere of radius (0.8±0.16) cm is

1) 0.2 
2) 0.6
3) 0.4
4) 0.04

25. The velocity of a body which has fallen freely under gravity varies as g^p h^q, where g is the acceleration due to gravity and h is the height through which it has fallen. The value of p and q are

26. The smallest division on the main scale of a vernier calliper is 0.5 mm. The scale has 50 divisions and these coincide with 25 main scale division, the least count of the calliper is

1) 0.05 mm
2) 0.01 mm
3) 0.50 mm
4) 0.25 mm

27. If Young’s modulus of a wire becomes quadrupled, then the ratio of the extensions of the wire before and after the increase of Young’s modulus will be (assuming other quantities to be constant)

1) 1 : 2
2) 1 : 4
3) 2 : 1
4) 4 : 1

28. The wreckage of the Titanic ship is at 3.8 km below the surface of water. The total pressure experienced at this depth is approximately (take density of sea water to be 1025 kg/m³, g = 10, P₀=1.01 bar)

1) 390 bar
2) 400 bar
3) 490 bar
4) 300 bar

29. A water tank is 100 m tall. It is filled with water such that the surface of water is at a distance of 20 m from the top of the tank. Suppose the tank has an orifice at a height of 50 m from the ground. The range of the water spilled out from the orifice is approximately

1) 100 m
2) 77 m
3) 63 m
4) 85 m

30. The curve surface area of a cylinder of radius 5.90 cm and height 10.10 cm with respect to the correct significant figures in cm² is (use π=3.14)

1) 374.8
2) 374.83
3) 375
4) None

31. The frequency (𝑣) of an oscillating liquid drop may depend upon radius (𝑟) of the drop, density (𝜌) of liquid and the surface tension (S) of the liquid as v=r^a ρ^b S^c. The values of a, b and c respectively are

32. Water flows in a horizontal pipe whose one end is closed with a valve. The reading of the pressure gauge attached to the pipe is P₁. The reading of the pressure gauge falls to P₂ when the valve is opened. The speed of water flowing in the pipe is proportional to

33. Bernoulli’s theorem is a consequence of conservation of

1) mass
2) momentum
3) angular momentum
4) energy

34. A metal cube of side 10 cm is subjected to a uniform stress of 20 MPa. As a result, its volume decreases by 2×10^-6m³. The compressibility of the cube is

1) 1 GPa^-1
2) 0.01 GPa^-1
3) 10 GPa^-1
4) 0.1 GPa^-1

35. The angle of a prism is A. One of its refracting surfaces is silvered. Light rays falling at an angle of incidence 2A on the first surface returns back through the same path after suffering reflection at the silvered . The refractive index. μ, of the prism is

1) 2sinA
2) 2cosA
3) 1/2cosA
4) tanA

36. Which of the following is not due to total internal reflection?

1) Working of optical fibre
2) Difference between apparent and real depth of a pond
3) Mirage on hot summer days
4) Brilliance of diamond

37. Two similar thin Equi-convex lenses, of focal f each, are kept coaxially in contact with each other such that the focal length of the combination is F1, When the space between the two lens is filled with glycerine (which has the same refractive index (μ=1.5) as that of glass) then the equivalent focal length is F2, the ratio F1:F2 will be

1) 3:4
2) 2:1
3) 1:2
4) 2:3

38. A metal plate is lying at the bottom of a tank full of a transparent liquid. Height of tank is 100 cm but the plate appears to be at 45 cm above bottom. The refractive index of liquid is

1) 1.00
2) 1.53
3) 1.81
4) 1.32

39. A ray of light falls on a glass slab making an angle of 45° with normal. The emergent ray makes the same angle with normal. It shows that

1) there is no refraction taking place
2) incident ray is perpendicular to emergent ray
3) emergent ray is parallel to the incident ray
4) the given case is not possible.

40. If ε₀and μ₀ are respectively the electric permittivity and the magnetic permeability of free space and ε and μ the corresponding quantities in a medium, the refractive index of the medium is

41. Two slits are separated by distance of 0.5cm and illuminate with light of λ=6000Å. If the screen is placed 2.5m from the slits. The distance of the third bright image from the centre will be

1) 9mm
2) 0.9cm
3) 0.9mm
4) 9cm

42. The interference pattern is obtained with two coherent light sources of intensity ratio 9n. In the interference pattern, the fringe visibility will be

43. A ray of light strikes a transparent rectangular slab of refractive index √2 at an angle of incidence of 45°. The angle between the reflected and refracted rays is

1) 105°
2) 305°
3) 205°
4) 405°

44. A ray of light is incident at 60° on one face of a prism of angle 30° and the emergent ray makes 30° with the incident ray. The refractive index of the prism is

1) 1.3
2) 1.4
3) 1.5
4) 1.7

45. The speed of light in media M1 and M2 are 1.5×10⁸ m/s and 2.0×10⁸ m/s respectively. A ray of light enters from medium M1 to M2 at an incidence angle ‘I’. If the ray suffers total internal reflection, the value of ‘I’ is.