MCQ
The velocity of light is maximum is :
- AAir
- BGlass
- CWater
- ✓Vacuum
✓
Answer
Correct option: D.
Vacuum
D
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 the diagram a graph between the intensity of $X-$rays emitted by a molybdenum target and the wavelength is shown, when electrons of $30 \ \text{keV}$ are incident on the target. In the graph one peak is of $\mathrm{K}_\alpha$ line and the other peak is of $\mathrm{K}_\alpha$ line and the other peak is of $\mathrm{K}_\beta$ line
→A caesium photocell, with a steady potential difference of 60V across, is illuminated by a bright point source of light 50 cm away. When the same light is placed 1m away the photoelectrons emitted from the cell (a) Are one quarter as numerous(b) Are half as numerous(c) Each carry one quarter of their previous momentum(d) Each carry one quarter of their previous energy
In a photoelectric experiment the stopping potential for the incident light of wavelength$4000\mathring{\text{A}}$ is 2 volt. If the wavelength be changed to $3000\mathring{\text{A}}$, the stopping potential will be?
→AM is used for broadcasting because(a) It is more noise immune than other modulation systems(b) It requires less transmitting power compared with other systems(c) Its use avoids receiver complexity(d) No other modulation system can provide the necessary bandwidth faithful transmission
If a wire of length 1 meter placed in uniform magnetic field 1.5 Tesla at angle 30° with magnetic field. The current in a wire 10 amp. Then force on a wire will be(a) 7.5 N(b) 1.5 N(c) 0.5 N (d) 2.5 N
Hydrogen atom excites energy level from fundamental state to n = 3. Number of spectrum lines according to Bohr, is(a) 4 (b) 3(c) 1 (d) 2
The resistance of the series combination of two resistance is S. When they are joined in parallel the total resistance is P. If S = nP, then the minimum possible value of n is(a) 4(b) 3(c) 2(d) 1
An electron is traveling along the x - direction. It encounters a magnetic field in the y - direction. Its subsequent motion will be:
Two long parallel wires carrying equal current separated by $1m,$ exert a force of $2 \times 10^{-7} \mathrm{~N} / \mathrm{m}$ on one another. The current flowing through them is
→The majority current carrier in $p$-type semi-conductor is :
→