MCQ
A photo cell is a device which:
- ✓Absorbs light and produces a stream of electrons
- BAbsorb a stream of electron and produces light
- CConverts protons into photons
- DConverts photons into protons
✓
Answer
Correct option: A.
Absorbs light and produces a stream of electrons
Photocell is a device which converts light energy into electrical energy. In photocell concave metallic cathode absorbs photons from incident light waves and emits electron from the metal surface towards anode.
In other words, it absorbs light and produces a stream of electrons.
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
When a $DC$ voltage of $200\, V$ is applied to a coil of self inductance $\frac{{2\sqrt 3 }}{\pi }\,H$, a current of $1\, A$ flows through it. But by replacing $DC$ source with $AC$ source of $200\, V$, the current in the coil is reduced to $0.5\, A$. Then, the frequency of $AC$ supply is......$Hz$
→A virtual and enlarged image of the object forms:
A charge q is placed at the centre of a cube. Then the flux passing through one face of cube will be
A charged particle (mass $m$ and charge $q$ ) moves along $X$ axis with velocity $V _{0}$. When it passes through the origin it enters a region having uniform electric field $\overrightarrow{ E }=- E \hat{ j }$ which extends upto $x = d$. Equation of path of electron in the region $x > d$ is
→The half-life period of radium is 1600 years. Its average life time will be
The primary and the secondary coils of a transformer contain $10$ and $100$ turns, respectively. The primary coil is connected to a battery that supplies a constant voltage of $1.5 \,V$. The voltage across the secondary coil is .................. $V$
→The magnetic field at the centre of a circular coil of radius $r$ carrying current $I$ is ${B_1}$. The field at the centre of another coil of radius $2 r$ carrying same current $I$ is ${B_2}$. The ratio $\frac{{{B_1}}}{{{B_2}}}$ is
→The work function of a metal is:
Internal forces can change :
3.8 days is the half-life period of a sample. After how many days, the sample will become 1/8th of the original substance