Question

A radio transmitter transmits at 830 kHz. At a certain distance from the transmitter magnetic field has amplitude $4.82 \times 10^{-11}T$. The electric field and the wavelength are respectively

• A. 0.014N/C, 36m
• B. 0.14N/C,36m
• C. 0.14N/C, 360m
• D. 0.014N/C,360m

Answer 1

Answer: (D)

0.014N/C,360m

Answer 2

Frequency of EM wave $\upsilon= 830\, KHz$ $= 830 \times 10^{3}\,Hz$. Magnetic field, $B = 4.82 \times 10^{-11} T$ As we know, frequency, $\upsilon = \frac{c}{\lambda}$ or $\lambda = \frac{c}{v} = \frac{3\times10^{8}}{830\times10^{3}}$ $\lambda \simeq 360\,m$ And, $E = BC = 4.82 \times 10^{-11} \times 3 \times 10^{8}$ $= 0.014 N/C$