MCQ
Given below are two statements : one is labelled as
Assertion (A) and other is labelled as Reason (R).
Assertion (A) : Electromagnetic waves carry energy but not momentum.
Reason (R): Mass of a photon is zero.
In the light of the above statements, choose the most appropriate answer from the options given below:
  • A
    (A) is true but (R) is false.
  • (A) is false but (R) is true.
  • C
    Both (A) and (R) are true but (R) is not the correct explanation of (A).
  • D
    Both (A) and (R) are true and (R) is the correct explanation of (A).

Answer

Correct option: B.
(A) is false but (R) is true.
(B)
Sol. Assertion is false because em waves have momentum.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

The acceleration due to gravity at height $h$ above the earth if $h \ll R$ (radius of earth) is given by
Electric potential in a region is varying according to the relation $V=\frac{3 x^2}{2}-\frac{y^2}{4}$, where $x$ and $y$ are in metre and $V$ is in volt. Electric field intensity (in $N/C$) at a point $(1 \,m , 2 \,m$ ) is ......
The equivalent capacitance of the combination shown in the figure is :
A radioactive material has a half-life of $8$ years. The activity of the material will decrease to about $1/8$ of its original value in .......... $years$
After absorbing a slowly moving neutron of mass $m_N$  $(momentum $~ $0)$ a nucleus of mass $M$ breaks into two nuclei of masses $m_1$ and $3m_1$ $(4m_1 = M + m_N)$, respectively. If the de Broglie wavelength of the nucleus with mass $m_1$ is $\lambda$, then de Broglie wavelength of the other nucleus will be
A shown in the figure, the amount of heat absorbed along the path $ABC$ is $90\,J$ and the amount of work done by the system is $30\,J$ . If the amount of work done along the path $ADC$ is $20\,J$ , the amount of heat absorbed will be  .... $J$
A ball is thrown vertically up ward. It has a speed of $10\;m/sec$ when it has reached one half of its maximum height. How high ($m$ માં) does the ball rise? (Take $g = 10 \;m/s^2$)
The coil of choke in a circuit
As shown in the figure, a network of resistors is connected to a battery of $2\,V$ with an internal resistance of $3\,\Omega$. The currents through the resistors $R_4$ and $R_5$ are $I_4$ and $I_5$ respectively. The values of $I_4$ and $I_5$ are :
In the circuit, as shown in the figure, if the value of $R.M.S$ current is $2.2$ ampere, the power factor of the box is