NEET Physics Electromagnetic Waves MCQs

Which of the following electromagnetic radiations has the highest penetrating power?

A wave propagating along a string is described by $y(x,t) = 0.005\sin(80.0x - 3.0t)$, where $x$ and $y$ are in meters and $t$ is in seconds. If the linear mass density of the string is $0.004\ kg/m$, what is the average power transmitted by the wave?

Light with an average flux of $25 \, W/cm^2$ falls on a non-reflecting surface at normal incidence having surface area $15 \, cm^2$. The energy received by the surface during time span of $1$ minute is:

A laser beam with a power of $120 \, W$ is spread uniformly over a circular area of radius $2 \, cm$. A non-reflecting surface within this area has a surface area of $5 \, cm^2$. Calculate the energy received by this surface in $30 \, seconds$.

A solar panel of area $0.5 \, m^2$ receives an average solar flux of $800 \, W/m^2$. If the panel absorbs $60\%$ of the incident energy, how much energy is absorbed in $1 \, hour$?

If a non-reflecting surface receives $100 \, J$ of energy in $5 \, seconds$ from a light source with a flux of $4 \, W/m^2$, what is the area of the surface?

Light with a flux of $1500 \, W/m^2$ falls on a perfectly absorbing surface. If the surface has dimensions $20 \, cm$ by $30 \, cm$, how much energy is absorbed in $10 \, minutes$?

Assume that a lamp radiates power $P$ uniformly in all directions. What is the magnitude of electric field strength at a distance r from the lamp?

The sun delivers ${10^4}{\rm{\;W}}{{\rm{m}}^{ - 2}}$ of electromagnetic flux to the earth’s surface. The total power that in incident on a roof of dimensions 10m square will be

The sun delivers ${10^4}{\rm{\;W}}{{\rm{m}}^{ - 2}}$ of electromagnetic flux to the earth’s surface. The total power that in incident on a roof of dimensions 10m square will be