MCQ
Amount of light entering into the camera depends upon
- AFocal length of the objective lens
- BProduct of focal length and diameter of the objective lens
- CDistance of the object from camera
- ✓Aperture setting of the camera
✓
Answer
Correct option: D.
Aperture setting of the camera
d
(d) An aperture is an hole through which light light enters the camera, if $N$ is the f-number, $f$ is focal length and $D$ the diameter of hole then amount of light entering into the camera is proportional aperture area.
(d) An aperture is an hole through which light light enters the camera, if $N$ is the f-number, $f$ is focal length and $D$ the diameter of hole then amount of light entering into the camera is proportional aperture area.
Area $=\frac{\pi D^{2}}{4}=\pi\left(\frac{f}{2 N}\right)^{2}$
Thus option $D$ is correct.
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 electrolytes, the mobile charges are:
Critical angle of incidence for a pair of optical media is $45^{\circ}$. The refractive indices of first and second media are in the ratio:
→To a germanium sample, traces of gallium are added as an impurity. The resultant sample would behave like
According to the classical theory, the circular path of the electrons is:
In order to pass 10% of main current through a moving coil galvanometer of 99 ohm, the resistance of the required shunt is
A proton and a deutron ( $\mathrm{q}=+\mathrm{e}, m=2.0 \mathrm{u})$ having same kinetic energies enter a region of uniform magnetic field $\vec{B}$, moving perpendicular to $\vec{B}$. The ratio of the radius $r_d$ of deutron path to the radius $r_p$ of the proton path is:
→A series $RLC$ circuit is activated by an $ac$ source of voltage $V_S$ volt and variable angular frequency $(\omega )$ as shown in the circuit. $V_{RL}$ and $V_C$ are the potential drops across $RL$ and $C$ respectively. Select the correct statement
→If in a voltaic cell 5 gm of zinc is consumed, then we get how many ampere hours ? (Given that E.C.E. of Zn is $3.387 \times 10^{-7}$ kg/coulomb)
→A capacitor of capacitance $C$ is charged to a potential $V$. The flux of the electric field through a closed surface enclosing the capacitor is:
→Infinite number of straight wires each carrying current $I$ are equally placed as shown in the figure. Adjacent wires have current in opposite direction. Net magnetic field at point $P$ is
→