CUET Level ll NEET Mock Test-1(Physics 2024-2025)

An ac source is connected to a capacitor C. Due to decrease in its operating frequency

• displacement current decreases

• capacitive reactance remains constant

• capacitive reactance decreases

• displacement current increases

In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of 2.0 x 10¹⁰ Hz and amplitude 48 V m^-1 . Then the amplitude of oscillating magnetic field is (Speed of light in free space = 3 x 10⁸ m s^-1)

• 1.6 x 10^-7 T

• 1.6 x 10^-6 T

• 1.6 x 10^-9 T

• 1.6 x 10^-8 T

When light propagates through a material medium of relative permittivity ε_r and relative permeability μ_r, the velocity of light, ν is given by (c-velocity of light in vacuum)

• ν = c

• ν = √μ_r/ε_r

• ν = √ε_r/μ_r

• ν = c/√ε_rμ_r

Match List-l with List-ll.

List-I List-ll

(Electromagnetic waves) (Wavelength)

(A) AM radio waves (i) 10^-10 m

(B) Microwaves (ii) 10² m

(C) Infrared radiations (iii) 10^-2 m

(D) X-rays (iv) 10^-4 m

• (A) - (iv), (B) - (iii), (C) - (ii), (D) - (i)

• (A) - (iii), (B) - (ii), (C) - (i), (D) - (iv)

• (A) - (iii), (B) - (iv), (C) - (ii), (D) - (i)

• (A) - (ii), (B) - ( iii), (C) - (iv),(D) - ( i)

A capacitor of capacitance 'C', is connected across an ac source of voltage V, given by V=V_O sinωt. The displacement current between the plates of the capacitor, would then be given by

• I_d = V₀ωCsinωt

• I_d = V₀ωCcosωt

• I_d = V₀/ωCcosωt

• I_d = V₀/ωCsinωt

For a plane electromagnetic wave propagating in ϰ-direction, which one of the following combination gives the correct possible directions for electric field (E) and magnetic field (B) respectively?

• • -ĵ + k, -ĵ + k

• • ĵ + k, ĵ + k

• • -ĵ + k, -ĵ - k

• • ĵ + k, -ĵ - k

Light with an average flux of 20 W/ cm² falls on a non-reflecting surface at normal incidence having surface area 20 cm². The energy received by the surface during time span of 1 minute is

• 10 x 10³ J

• 12 x 10³ J

• 24 x 10³ J

• 48 x 10³ J

The ratio of contributions made by the electric field and magnetic field components to the intensity of an electromagnetic wave is ( c = speed of electromagnetic waves )

• c : 1

• 1 : 1

• 1 : c

• 1 : c²

A parallel plate capactior of capacitance 20 μF is being charged by a voltage source whose potential is changing at the rate of 3 Vs^-1 . The conduction current through the connecting wires, and the displacement current through the plates of the capacitor, would be, respectively

• zero, zero

• zero, 60 μF

• 60 μA, 60 μA

• 60 μA, zero

For a transparent medium relative permeability and permittivity, μ_r and ε_r are 1.0 and 1.44 respectively. The velocity of light in this medium would be

• 2.5 x 10⁸ m s^-1

• 3 x 10⁸ m s^-1

• 2.08 x 10⁸ m s^-1

• 4.32 x 10⁸ m s^-1