MCQ
Lux is a unit of
- ALuminous intensity of a source
- ✓Illuminance on a surface
- CTransmission coefficient of a surface
- DLuminous efficiency of source of light
✓
Answer
Correct option: B.
Illuminance on a surface
b
( b)
( b)
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
The mass defect per nucleon is called:
A spider and a fly are on opposite side of surface of glass sphere. What must be the maximum range of solid angle, where the fly can be seen by the spider.
→Given : dimension of spider and fly is very small $w.r .t.$ to sphere $RI$ of glass $μ_g = \sqrt 2$
Which of the following quantities is zero on an average for the molecules of an ideal gas in equilibrium?
The current of $5 \mathrm{~A}$ flows in a square loop of sides $1$ $\mathrm{m}$ is placed in air. The magnetic field at the centre of the loop is $\mathrm{X} \sqrt{2} \times 10^{-7} \mathrm{~T}$. The value of $\mathrm{X}$ is____.
→A divergent lens will produce
In the $EM$ wave the amplitude of magnetic field $H_0$ and the amplitude of electric field $E_o$ at any place are related as
→Ultraviolet radiations of $6.2\,eV$ falls on an aluminium surface (work function $4.2\;eV$). The kinetic energy in joules of the fastest electron emitted is approximately
→A nucleus $_Z{X^A}$ emits $3 \alpha$ - particles and $5 \beta$ particle. The ratio of total neutrons and protons in the final nucleus is
→Three long current carrying wires $P, Q$ and $R$ placed perpendicular to plane of the paper. Magnetic force per unit length on wire $'R'$ is
→The activity of a sample reduces from $A_0$ to ${A_0} / \sqrt{3}$ in one hour. The activity after $3$ hours more will be
→