MCQ
Two identical light sources $S_1$ and $S_2$ emit light of same wavelength $\lambda$. These light rays will exhibit interference if
  • Their phase differences remain constant
  • B
    Their phases are distributed randomly
  • C
    Their light intensities remain constant
  • D
    Their light intensities change randomly

Answer

Correct option: A.
Their phase differences remain constant
a
(a)For interference phase difference must be constant.

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 coefficient of friction between the tyres and the road is $0.25$. The maximum speed with which a car can be driven round a curve of radius $40 \,m$ without skidding is ........ $ms^{-1}$ (assume $g = 10 \,ms^{-2}$)
Consider the wall of a dam to be straight with height $H$ and length $L$. It holds a lake of water of height $h (h < H)$ on one side. Let the density of water be $\rho_{ w }$. Denote the torque about the axis along the bottom length of the wall by $\tau_1$. Denote also a similar torque due to the water up to height $h / 2$ and wall length $L / 2$ by $\tau_2$. Then $\tau_1 / \tau_2$ (ignore atmospheric pressure) is
Find maximum amplitude for safe $SHM$ (block does not topple during $SHM$) of $a$ cubical block of side $'a'$ on a smooth horizontal floor as shown in figure (spring is massless)
A student in a town in India, where the price per unit ( $1$ unit $=1 \,kWh$ ) of electricity is $₹ 5.00$, purchases a $1 \,kVA$ $UPS$ (uninterrupted power supply) battery. A day before the exam, $10$ friends arrive to the student's home with their laptops and all connect their laptops to the $UPS$. Assume that each laptop has a constant power requirement of $90 \,W$. Consider the following statements.

$I.$ All the $10$ laptops can be powered by the $UPS$, if connected directly.

$II.$ All the $10$ laptops can be powered, if connected using an extension box with a $3 \,A$ fuse.

$III.$ If all the $10$ friends use the laptop for $5 \,h$, then the cost of the consumed electricity is about $₹ 22.50.$

Select the correct option with the true statements.

Two men are walking along a horizontal straight line in the same direction. The man in front walks at a speed $1.0 m s ^{-1}$ and the man behind walks at a speed $2.0 ms ^{-1}$. A third man is standing at a height $12 m$ above the same horizontal line such that all three men are in a vertical plane. The two walking men are blowing identical whistles which emit a sound of frequency $1430 Hz$. The speed of sound in air is $330 m s ^{-1}$. At the instant, when the moving men are $10 m$ apart, the stationary man is equidistant from them. The frequency of beats in $Hz$, heard by the stationary man at this instant, is. . . . . 
The photo-electrons emitted from a surface of sodium metal are such that
$10\,gm$ of ice at $0\,^oC$ is mixed with $'m'\,gm$ of water at $50\,^oC$ . ........ $gm$ is minimum value of $m$ so that ice melts completely. ( $L_f = 80\,cal/gm$ and $S_W = 1\,cal/gm-\,^oC$ )
Find equivalent capacitance across $AB$.....$ \mu F$ (all capacitances in $\mu F$)
Two objects are rubbed against each other, the nature of electric force, when they are placed at some distance is
A block of ice at $-20\,^oC$ having a mass of $2\, kg$ is added to a $3\, kg$ water at $15\,^oC$. Neglecting heat losses and the heat capacity of the container