Download App

Electromagnetic Waves — Physics STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 SciencePhysicsElectromagnetic Waves3 Marks
Question
Consider the situation of the previous problem. Define displacement resistance $\text{R}_\text{d}=\frac{\text{V}}{\text{i}_\text{d}}$ of the space between the plates, where V is the potential difference between the plates and id is the displacement current. Show that Rd varies with time as $\text{R}_\text{d}=\text{R}\big(\text{e}^{\text{t}/\tau}-1\big)$ 
✓

Answer

$\text{E}=\frac{\text{Q}}{\in_0\text{A}}$ (Electric field)
$\phi=\text{E.A.}=\frac{\text{Q}}{\in_0\text{A}}\frac{\text{A}}{2}=\frac{\text{Q}}{\in_02}$
$\text{i}_0=\in_0\frac{\text{d}\phi_\text{E}}{\text{dt}}=\in_0\frac{\text{d}}{\text{dt}}\Big(\frac{\text{Q}}{\in_02}\Big)$
$=\frac{1}{2}\Big(\frac{\text{dQ}}{\text{dt}}\Big)$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "3 Marks Question" from Electromagnetic Waves→Electromagnetic Waves — all question types→Physics STD 12 Science question papers→Bihar Board STD 12 Science question papers→Bihar Board question paper generator→

Similar questions

If the bar magnet in exercise 5.13 is turned around by 180°, where will the new null points be located?
→
Careful measurement of the electric field at the surface of a black box indicates that the net outward flux passing through the surface of the box is $8.0 \times 10^3 Nm ^2 / C$.
(a) What is the net charge inside the box?
(b) If the net outward flux through the surface of the box were zero, could you conclude that there were no charges inside the box? Why or why not?
→
A straight, long wire carries a current of 20A. Another wire carrying equal current is placed parallel to it. If the. force acting on a length of 10cm of the second wire is 2 ×10-5N, what is the separation between them?
→
Explain the experiment which represents the total internal reflection.
→
The maximum speed and acceleration of a particle executing simple harmonic motion are 10cm/s and 50cm/s2. Find the position(s) of the particle when the speed is 8cm/s.
→
Figure shows the graph of velocity versus time for a particle going along the X-axis. Find:
  1. The acceleration.
  2. The distance travelled in 0 to 10s.
  3. The displacement in 0 to 10s.

→
A closely wound solenoid 80 cm long has 5 layers of windings of 400 turns each. The diameter of the solenoid is 1.8 cm. If the current carried is 8.0 A, estimate the magnitude of B inside the solenoid near its centre.
→
You have learnt in the text how Huygens’ principle leads to the laws of reflection and refraction. Use the same principle to deduce directly that a point object placed in front of a plane mirror produces a virtual image whose distance from the mirror is equal to the object distance from the mirror.
→
The energy flux of sunlight reaching the surface of the earth is $1.388 \times 10^3 W / m ^2$. How many photons (nearly) per square metre are incident on the Earth per second? Assume that the photons in the sunlight have an average wavelength of 550 nm .
→
Consider Fig. for photoemission.
How would you reconcile with momentum-conservation? Note light (photons) have momentum in a different direction than the emitted electrons.

→