Question
What is wave-front ?

Answer

Wave-front : A wave is a disturbance starting from a light source (say origin) which propagates around the source in all possible directions in homogeneous medium ether. Thus particles of ether start vibrating. At any instant for the same distance from the source all particles are in the same phase.

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

Similar questions

(a) Calculate the potential at a point $P$ located at a distance of 9 cm due to the charge $4 \times 10^{-7} C$.(b) Now, find the work done in bringing the charge $2 \times 10^{-9} C$ from infinity to point P . Does the answer depend on the path along which the charge is brought?
If we walk barefoot on a nylon mat for some time and touch the metal handle of a door, we get an electric shock. Why does this happen?
Explain Rutherford's nuclear model of the atom.
An inductor is connected to a battery through a switch. Explain why the emf induced in the inductor is much larger when the switch is opened as compared to the emf induced when the switch is closed.
In a series $\text{LCR}$ circuit, the voltage across an inductor, a capacitor and a resistor are $30V, 30V$ and $60V$ respectively. What is the phase difference between the applied voltage and current in the circuit?
The distance of the field point on the axis of a small dipole is doubled. By what factor will the electric field, due to the dipole change?
Is there any lower limit to the electric force between two particles placed at a separation of 1cm ?
A modulating signal is a square wave, as shown in Fig.

The carrier wave is given by $c(t) = 2\sin (8\pi t)$ volts.
  1. Sketch the amplitude modulated waveform,
  2. What is the modulation index?
Answer the following questions:
Why is choke coil needed in the use of fluorescent tubes with acmains? Why can we not use an ordinary resistor instead of the choke coil?
Three capacitors each of capacitance 9 pF are connected in series.
  1. What is the total capacitance of the combination?
  2. What is the potential difference across each capacitor if the combination is connected to a 120 V supply?