MCQ
If threshold wavelength for sodium is 6800Å then the work function will be
- ✓1.8 eV
- B2.5 eV
- C2.1 eV
- D1.4 eV
✓
Answer
Correct option: A.
1.8 eV
1.8 eV
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
In an $a.c.$ circuit the voltage applied is $E=E_o$ $sin$$\omega t$ The resulting current in the circuit is $I=I_osin$$\left( {\omega t - \frac{\pi }{2}} \right)$ .The power consumption in the circuit is given by
→In the Young's double slit experiment, the intensities at two points $P_1$ and $P_2$ on the screen are respectively $I_1$ and $I_2$. If $P_1$ is located at the centre of a bright fringe and $P_2$ is located at a distance equal to a quarter of fringe width from $P_1$, then $I_1$/$I_2$ is :
→Two plano-convex lenses each of focal length $10\,cm$ and refractive index $3/2$ placed as shown in fig. In space left, water $\left( {\mu = \frac{4}{3}} \right)$ is filled.
→The whole arrangement is in air. The optical power of the system is .......$D$
In the diagram, the input is across the terminals $A$ and $C$ and the output is across the terminals $ B $ and $D$, then the output is
→A radioactive sample is $a-$emitter with half life $138.6$ days is observed by a student to have $2000$ disintegration$/\sec.$ The number of radioactive nuclei for given activity are
→A proton is projected with velocity $\overrightarrow{ V }=2 \hat{ i }$ in a region where magnetic field $\overrightarrow{ B }=(\hat{i}+3 \hat{j}+4 \hat{k})\; \mu T$ and electric field $\overrightarrow{ E }=10 \hat{ i } \;\mu V / m .$ Then find out the net acceleration of proton (in $m / s ^{2}$)
→At a certain place a magnet makes 30 oscillations per minute. At another place where the magnetic field is double, its time period will be
Which of the following mirrors is used in searchlight?
When the length and area of cross-section both are doubled, then its resistance
The net charge in a current carrying wire is zero still magnetic field exerts a force on it, because a magnetic field exerts force on