MCQ
Photoelectric effect was successfully explained first by
  • A
    Planck
  • B
    Hallwash
  • C
    Hertz
  • Einstein

Answer

Correct option: D.
Einstein
d
(d) Einstein successfully explained the photoelectric effect using the assumption $E= hv.$ This assumption is given by Planck. Einstein showed that not only light is quantized but also atomic vibrations are quantized. He was able to explain this result by assuming that the oscillations of atoms are quantized according to $E=$ $n h \nu$

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

A car is moving along a straight road with a uniform acceleration. It passes through two points $P$ and $Q$ separated by a distance with velocity $30\; km / h$ and $40\; km / h$ respectively. The velocity of the car midway between $P$ and $Q$
A dancer moves counterclockwise at constant speed around the path shown below. The path is such that the lengths of its segments, $PQ, QR, RS$, and $SP$, are equal. Arcs $QR$ and $SP$ are semicircles. Which of the following best represents the magnitude of the dancer’s acceleration as a function of time $t$ during one trip around the path, beginning at point $P$ ?
In Guericke's experiment to show the effect of atmospheric pressure, two copper hemispheres were tightly fitted to each other to form a hollow sphere and the air from the sphere was pumped out to create vacuum inside. If the radius of each hemisphere is $R$ and the atmospheric pressure is $p$, then the minimum force required (when the two hemispheres are pulled apart by the same force) to separate the hemispheres is
In $YDSE$ how many maxima can be obtained on the screen if wavelength of light used is $200\,nm$ and $d = 700\, nm:$
Two blocks $A$ and $B$ of masses $6\, kg$ and $3\, kg$ rest on a smooth horizontal surface as shown in the figure. If coefficient of friction between $A$ and $B$ is $0.4$, the maximum horizontal force which can make them without separation is  ........ $N$ 
In an $LCR $ circuit as shown below both switches are open initially. Now switch $S_1$ is closed, $S_2$ kept open. ( $q$ is charge on the capacitor and $\tau = RC$ is Capacitive time constant). Which of the following statement is correct?
Before using the tangent galvanometer, its coil is set in
Temperature difference of $120\,^oC$ is maintained between two ends of a uniform rod $AB$ of length $2L$. Another bent rod $PQ$, of same cross-section as $AB$ and length $\frac{{3L}}{2}$,  is connected across $AB$ (See figure). In steady state, temperature difference between $P$ and $Q$ will be close to .......... $^oC$
$PQR$ is a right angled prism with other angles as $60^o$ and $30^o$. Refractive index of prism is $1.5$. $PQ$ has a thin layer of liquid. Light falls normally on the face $PR$. For total internal reflection, maximum refractive index of liquid is
The current in a coil changes from $4$ $ampere$ to zero in $0.1$ $s$. If the average $e.m.f. $induced is $100 \,volt$, what is the self inductance of the coil.....$H$