Home
Class 12
PHYSICS
The magnetic field of a plane electromag...

The magnetic field of a plane electromagnetic wave is given by: `vec(B)=B_(0)hat(i)[cos(kz- omegat)]+B_(1)hat(j)cos(kz+omegat)` where `B_(0)=3xx10^(-5)T` and `B_(1)=2xx10^(-6)T`. The rms value of the force experienced by a stationary charge `Q=10^(-4)C` at `z=0` is close to:

A

0.1 N

B

`3xx10^(-2)N`

C

0.6 N

D

0.9 N

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the RMS value of the force experienced by a stationary charge \( Q = 10^{-4} \, \text{C} \) at \( z = 0 \) due to the given magnetic field of the electromagnetic wave. ### Step-by-Step Solution: 1. **Identify the Magnetic Field**: The magnetic field is given by: \[ \vec{B} = B_0 \hat{i} \cos(kz - \omega t) + B_1 \hat{j} \cos(kz + \omega t) \] where \( B_0 = 3 \times 10^{-5} \, \text{T} \) and \( B_1 = 2 \times 10^{-6} \, \text{T} \). 2. **Calculate the Electric Field**: The electric field \( \vec{E} \) in an electromagnetic wave can be calculated using the relation: \[ \vec{E} = c \vec{B} \] where \( c \) is the speed of light, approximately \( 3 \times 10^8 \, \text{m/s} \). Thus, we can calculate \( \vec{E} \): \[ \vec{E} = 3 \times 10^8 \left( B_0 \hat{i} \cos(kz - \omega t) + B_1 \hat{j} \cos(kz + \omega t) \right) \] Substituting the values of \( B_0 \) and \( B_1 \): \[ \vec{E} = 3 \times 10^8 \left( 3 \times 10^{-5} \hat{i} \cos(kz - \omega t) + 2 \times 10^{-6} \hat{j} \cos(kz + \omega t) \right) \] 3. **Evaluate \( \vec{E} \) at \( z = 0 \)**: At \( z = 0 \): \[ \vec{E} = 3 \times 10^8 \left( 3 \times 10^{-5} \hat{i} \cos(-\omega t) + 2 \times 10^{-6} \hat{j} \cos(\omega t) \right) \] This simplifies to: \[ \vec{E} = 3 \times 10^8 \left( 3 \times 10^{-5} \hat{i} \cos(\omega t) + 2 \times 10^{-6} \hat{j} \cos(\omega t) \right) \] 4. **Calculate the Force on the Charge**: The force \( \vec{F} \) on a charge \( Q \) in an electric field \( \vec{E} \) is given by: \[ \vec{F} = Q \vec{E} \] Substituting \( Q = 10^{-4} \, \text{C} \): \[ \vec{F} = 10^{-4} \cdot \vec{E} \] 5. **Magnitude of the Force**: The magnitude of the electric field \( \vec{E} \) can be calculated: \[ |\vec{E}| = 3 \times 10^8 \sqrt{(3 \times 10^{-5})^2 + (2 \times 10^{-6})^2} \] Calculate the components: \[ |\vec{E}| = 3 \times 10^8 \sqrt{(9 \times 10^{-10}) + (4 \times 10^{-12})} = 3 \times 10^8 \sqrt{9.04 \times 10^{-10}} \] 6. **Calculate the RMS Force**: The RMS value of the force is given by: \[ F_{\text{RMS}} = \frac{F}{\sqrt{2}} \] where \( F \) is the average force calculated from the magnitude of \( \vec{F} \). 7. **Final Calculation**: After calculating the magnitude of \( \vec{F} \) and applying the RMS formula, we can find the final answer. ### Final Answer: The RMS value of the force experienced by the charge is approximately \( 0.6 \, \text{N} \).

To solve the problem, we need to find the RMS value of the force experienced by a stationary charge \( Q = 10^{-4} \, \text{C} \) at \( z = 0 \) due to the given magnetic field of the electromagnetic wave. ### Step-by-Step Solution: 1. **Identify the Magnetic Field**: The magnetic field is given by: \[ \vec{B} = B_0 \hat{i} \cos(kz - \omega t) + B_1 \hat{j} \cos(kz + \omega t) ...
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • JEE MAIN REVISION TEST - 10| JEE -2020

    VMC MODULES ENGLISH|Exercise PHYSICS (SECTION 2)|5 Videos
  • JEE MAIN REVISION TEST - 13

    VMC MODULES ENGLISH|Exercise PHYSICS (SECTION 2)|5 Videos

Similar Questions

Explore conceptually related problems

The electric field of a plane electromagnetic wave is given by vec(E)=E_0haticos(kz)cos(omegat) The corresponding magnetic field vec(B) is then given by :

Magnetic field in a plane electromagnetic wave is given by bar(B) = B_(0)"sin"(kx + omegat)hat(j)T Expression for corresponding electric field will be

Magnetic field in a plane electromagnetic wave is given by bar(B) = B_(0)"sin"(kx + omegat)hat(j)T Expression for corresponding electric field will be

The magnetic field in a plane electromagnetic wave is given by B_(y) = 2 xx 10^(-7) sin (0.5 xx 10^(3)x + 1.5 xx 10^(11) t) . This electromagnetic wave is

The magnetic field in a plane electromagnetic wave is given by vecB=2×10^-7 [sin(0.5×10^3x+1.5×10^(11)t)hatj] . The electric field is given by (where B is in T , x is in m and t in s)

The magnetic field in a plane electromagnetic wave is given by B = 200 (muT) sin 4 xx 10'^(-5)s^(1) (t-x//c) . Find the maximum magnetic and electric fields.

The magnetic field in the plane electromagnetic wave is given by B_(z)=2xx10^(-7) sin(0.5xx10^(3)x+1.5xx10^(11)t) tesla. The expression for electric field will be:

If the magnetic field in a plane electromagnetic wave is given by vec(B) = 6 xx 10^(-8) sin (1.6 xx 10^(3) x + 48 xx 10^(10)t) hatj T ,. What will be expression for electric filed ?

If the magnetic field in a plane electromagnetic wave is given by vec(B) = 6 xx 10^(-8) sin (1.6 xx 10^(3) x + 48 xx 10^(10)t) hatj T ,. What will be expression for electric filed ?

The magnetic field in a plane electromagnetic wave is given by B_(y) = 2xx10^7 T sin (0.5xx10^3x+1.5xx10^11 t) T (a) What is the wavelength and frequency of the wave? (b) Write an expression for the eletric field.