Question
$X-$ rays were discovered by

Answer

(b) Roentgen, a German physicist accidentally discovered the $x$ - rays on November $8,1895 .$ working with a cathode-rays tube is his laboratory, Roentgen observed a flue scent glow of crystals on a table near his tube.

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

An ideal coil of $10\ H$ is connected in series with a resistance of $5\ \omega$ and a battery of $5\ V.\ 2$ second after the connection is made, the current flowing in ampere in the circuit is
If a slab of insulating material $4 \times {10^{ - 3}}\,m$ thick is introduced between the plates of a parallel plate capacitor, the separation between plates has to be increased by $3.5 \times {10^{ - 3}}\,m$ to restore the capacity to original value. The dielectric constant of the material will be
In the electric network shown, when no current flows through the $4 \Omega$ resistor in the arm EB, the potential difference between the points $A$ and $D$ will be $.............\,V$
Two spheres $P$ and $Q$ of equal masses are attached to a string of length $2\,\, m$ as shown in figure. The string and the spheres are then whirled in a horizontal circle about $O$ at a constant rate. What is the value of the ratio
$\left( {\frac{{{\text{Tension in the string between P and Q}}}}{{{\text{Tension in the string between P and O}}}}} \right)?$
A large ship can float but a steel needle sinks because of
A particle of mass $m$ and charge $q$, accelerated by a potential difference $V$ enters a region of a uniform transverse magnetic field $B$. If $d$ is the thickness of the region of $B$, the angle $\theta$ through which the particle deviates from the initial direction on leaving the region is given by
A fighter plane is flying horizontally at a height of $250\  m$ from ground with constant velocity of $500\  m/s$. It passes exactly over a cannon which can fire a shell at any time in any direction with a speed of  $100\  m/s$. Find the duration of time  for which the plane is in danger of being hit by a cannon shell
If the temperature of sink is at absolute zero, then the efficiency of Carnot engine will be ........ $\%$
${M_n}$ and ${M_p}$ represent mass of neutron and proton respectively. If an element having atomic mass $M$ has $N-$neutron and $Z-$proton, then the correct relation will be
An electron moving with the speed $5 \times {10^6}$ per sec is shooted parallel to the electric field of intensity $1 \times {10^3}\,N/C$. Field is responsible for the retardation of motion of electron. Now evaluate the distance travelled by the electron before coming to rest for an instant (mass of $e = 9 \times {10^{ - 31}}\,Kg.$ charge $ = 1.6 \times {10^{ - 19}}\,C)$