The velocity of electromagnetic radiation in a medium of permittivity ε₀
The velocity of electromagnetic radiation in a medium of permittivity ε₀ and permeability μ₀ is given by
Options
(a) √(ε₀ / μ₀) (b) √(μ₀ ε₀) (c) 1 / √(μ₀ ε₀) (d) √(μ₀ / ε₀)
Physics
The condition under which a microwave oven heats up a food item containing
The condition under which a microwave oven heats up a food item containing water molecules most efficiently is
Options
(a) the frequency of the microwave must match the resonant frequency of the water […]
The electromagnetic waves detected using a thermopile and used in physical therapy
The electromagnetic waves detected using a thermopile and used in physical therapy are
Options
(a) gamma radiations (b) x-rays (c) ultraviolet radiations (d) infrared radiations
Correct Answer:
infrared radiations
Explanation:
The electromagnetic waves […]
In electromagnetic spectrum, the frequencies of γ-rays and x-rays and ultraviolet rays
In electromagnetic spectrum, the frequencies of γ-rays and x-rays and ultraviolet rays are denoted by n₁,n₂ and n₃ respectively, then
Options
(a) n₁>n₂>n₃ (b) n₁n₃
Explanation:
Frequency range of ultraviolet rays ≃ 10¹⁶ […]
A plane electromagnetic wave of frequency 20 MHz travels through a space along
A plane electromagnetic wave of frequency 20 MHz travels through a space along x-direction. If the electric field vector at a certain point in space is 6 Vm⁻¹, then what is the magnetic field vector […]
The speed of electromagnetic waves in vaccum is equal to
The speed of electromagnetic waves in vaccum is equal to
Options
(a) μ₀ε₀ (b) √(μ₀ε₀) (c) 1/√(μ₀ε₀) (d) 1/(μ₀ε₀)
Correct Answer:
1/√(μ₀ε₀)
Explanation:
According to Maxwelll, it is found that the electromagnetic waves […]
A jar is filled with two non-mixing liquids 1 and 2 having densities
A jar is filled with two non-mixing liquids 1 and 2 having densities ρ₁ and ρ₂ respectively. A solid ball, made of a material of density ρ₃, is dropped in the jar. It comes to […]
In the given (V – T) diagram, what is the relation between pressure P₁ and P₂?
In the given (V – T) diagram, what is the relation between pressure P₁ and P₂?
Options
(a) P₂ > P₁ (b) P₂ < P₁ (c) Cannot be predicted (d) P₂ = P₁
At what temperature will the rms speed of air molecules be double that of NTP?
At what temperature will the rms speed of air molecules be double that of NTP?
Options
(a) 519⁰C (b) 619⁰C (c) 719⁰C (d) 819⁰C
Correct Answer:
819⁰C
Explanation:
v(rms) = √(3RT / M) […]
Six molecules have speeds 2 units, 5 units, 3 units, 6 units, 3 units and 5 units
Six molecules have speeds 2 units, 5 units, 3 units, 6 units, 3 units and 5 units respectively. The rms speed is
Options
(a) 4 units (b) 1.7 units (c) 4.2 units (d) […]