NEET INTRODUCTORY TEST SERIES 7 PHYSICS

1. A square of wire of side 3 cm is placed at a distance of 25 cm from a concave mirror of focal length 10 cm. The centre of the square is at the axis of the mirror and the plane is normal to the axis. The area enclosed by the image of the wire is

(a) 4 cm²
(b) 6 cm²
(c) 16 cm²
(d) 36 cm²

2. The light ray is incidence at angle of 60 on a prism of angle 45 . When the light ray falls on the other surface at 90  from the surface, the refractive index of the material of prism  and the angle of deviation  are given by

3. The focal lengths of the lenses of an astronomical telescope are 50 cm and 5 cm. The length of the telescope when the image is formed at the least distance of distinct vision is

(a) 45 cm
(b) 55 cm
(c) 275 6 cm
(d) 325 6 cm

4. A point object is moving on the principal axis of a concave mirror of focal length 24 cm towards the mirror. When it is at a distance of 60 cm from the mirror, its velocity is 9 cm/sec. What is the velocity of the image at that instant?

(a) 5 cm/sec
(b) 12 cm/sec
(c) 4 cm/sec
(d) 9 cm/sec

5. Radius of curvature of concave mirror is 10 cm and the size of image is twice as that of object, then the object distance is

(a) 60 cm
(b) 20 cm
(c) 40 cm 
(d) 30 cm

6. Two thin lenses of focal lengths f₁ and f₂ are in contact and coaxial. The combination is equivalent to a single lens of power

7. A point object O is placed in front of a glass rod having spherical end of radius of curvature 30 cm. The image would be formed be

(a) 30 cm left 
(b) infinity
(c) 1 cm to the right
(d) 18 cm to the left

8. Relation between critical angles of water and glass is

a) C_w > C_g
b) C_w < C_g
c) C_w = C_g
(a) C_w = C_g= 0

9. The force between two points charges placed in vacuum at distance 1 mm is 18 N. If a glass plate of thickness 1 mm and dielectric constant 6, be kept between the charges then new force between them would be

(a) 18 N
(b) 108 N         
(c) 3 N
(d) 3×10^-6 N

10. A charge Q is divided in two parts Q₁ and Q₂ and these charges are placed at distance . There will be maximum repulsion between them, when

(a) Q₂= (Q/R), Q₁=Q-(Q/R)
(b) Q₂= (Q/3), Q₁=(2Q/3)
(c) Q₂= (Q/4), Q₁=(3Q/4)
(d) Q₂= Q₂= (Q/2)

11. The inward and outward electric flux for a closed surface in units of N-m²/C are respectively 8×10³ and 4×10³. Then the total charge inside the surface is
[where ε₀= permittivity constant]

12. Find the total flux due to charge associated with the given hemispherical surface

13. Three capacitors of capacitance 4 μF, 6 μF and 12 μF are connected first in series and then in parallel. What is the ratio of equivalent capacitance in the two cases?

(a) 2:3
(b) 1:11
(c) 11:1
(d) 1:3

14. What is the equivalent capacitance of the system of capacitors between A and B?

15. A 2 m long wire has a resistance of 16 Ω. What is the resistance of this wire if it is 1 m long?

(a) 4 Ω
(b) 8 Ω            
(c) 32 Ω
(d) 64 Ω

16. What is the value of unknown resistance R, if galvanometer shows null deflection in the given meter bridge set up?

(a) 97.50 Ω 
(b) 105 Ω         
(c) 150 Ω
(d) 110 Ω

19. Position of a particle in a horizontal plane is given by x= 6t m and y=8t-5t² m. The velocity with which the particle starts moving?