CUET Level - II JEE Mock Test - 1(Physics)

Two charges each equal to q, are kept at x = -a and x = a on the x-axis. A particle of mass m and charge q₀ =q/2 is placed at the origin. If charge q₀ is given a small displacement (y<<a) along the y-axis, the net force acting on the particle is proportional to

• y
• • - 1/y

• • - y

• 1/y

The region between two concentric spheres of radii 'a' and 'b', respectively has volume charge density ρ = A/r, where A is a constant and r is the distance from the Centre. At the Centre of the sphere is a point charge Q. The value of A such that the electric field in the region between the spheres will be constant is :

• A = Q/(2π(b² - a²))

• A = Q/2πa²

• A = 2Q/(π(a² - b²))

• A = 2Q/πa²

An electric dipole is placed at an angle of 30⁰ with an electric field intensity 2 X 10⁵ N C^-1. It experiences a torque equal to 4 N m. The charge on the dipole. if the dipole length is 2 cm, is

• 8 mC

• 2 mC

• 5 mC

• 7 μC

An electric dipole has a fixed dipole moment P̅, which makes angle θ with respect to x-axis. When subjected to an electric field E̅₁ = E^_i, it experiences a torque T̅₁ = ζ k^ . When subjected to another electric field E̅_{2 =} √3E₁j^ it experiences a torque T̅₂ = -T̅_{1 .} The angle θ is

• 30⁰

• 45⁰

• 60⁰

• 90⁰

The correct statement about dielectric dipole is

• The total charge of an charge dielectric dipole is non-zero.

• The electric field of an dielectric dipole at far-off distances (r
  ) varies as 1/r².

• The dipole moment vector of an electric dipole points -q to +q .

• The electric dipole moment of CO₂molecule is non - zero in electric field free region.

A charge 'q' is placed at the Centre of the line joining two equal charges 'Q'. The system of the three charges will be in equilibrium if 'q' is equal to

• Q/4
• Q/2
• -Q/4
• -Q/2

A thin disc of radius b = 2a has a concentric hole of radius a in it (see figure). It carries uniform surface charge σ on it. If the electric field on its axis at height h (h<<a) from its Centre is given as Ch then value of C is

• σ/aε₀

• σ/2aε₀

• σ/4aε₀

• σ/8aε₀

A combination of parallel plate capacitors is maintained at a certain potential difference.

When a 3mm thick slab is introduced between all the plates, in order to maintain the same potential difference, the distance between the plates is increased by 2.4mm. Find the dielectric constant of the slab.

• 6

• 5

• 4

• 3

A uniformly charged solid sphere of radius R has potential V₀ (measured with respect to ∞ ) on its surface. For this sphere the equipotential surfaces with potentials 3V₀ /2, 5V₀ /4, 3V₀ /4 and V₀ /4 have radius R_1, R_2,R₃ and R₄ respectively. Then

• R1 = 0 and R2 < (R4 - R3)

• 8R < R4

• R1 = 0 and R2 > ( R4 - R3)

• R1 = 0 and (R2 - R1) > (R4 - R3)

The potential (in volts) of a charge distribution is given by

V_(z) =30 - 5_z² for ∣z∣ ≤ 1 m

V_(z) =35 - 10 ∣z∣ for ∣z∣ ≥ 1 m.

V_(z) does not depend on x and y. If this potential is generated by a constant charge per unit volume ρ₀ (in units of ξ₀) which is spread over a certain region, then choose the correct statement.

• ρ₀ = 20 ξ₀ in the entire region.

• ρ₀ = 10 ξ₀ for |z| ≤ 1 m and ρ₀ = 0 elsewhere

• ρ₀ = 20 ξ₀ for |z| ≤ 1 m and ρ₀ = 0 elsewhere

• ρ₀ = 40 ξ₀ in the entire region.