Question
State the research done by scientists on electromagnetism after Oersted's observation.

Answer

After the observation of Oersted, in 1864 James Maxwell examined the laws governing electricity and magnetism and concluded that light is an electromagnetic wave.
Scientist Hertz discovered radio waves and, Jagdish Bose, Marconi produced radio waves experimentally by the end of the $19^{\text {th }}$ century.
This led to the invention of devices for generation, amplification, transmission and detection of electromagnetic waves in the $20^{\text {th }}$ century.

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 cell of emf $E$ and internal resistance $r$ is connected to two external resistances $R_1$ and $R_2$ and a perfect ammeter.The current in the circuit is measured in four different situations:
i. Without any external resistance in the circuit.
ii. With resistance $\mathrm{R}_1$ only.
iii. With $R_1$ and $R_2$ in series combination.
iv. With $R_1$ and $R_2$ in parallel combination.
The currents measured in the four cases are 0.42 A, 1.05 A, 1.4 A and 4.2 A, but not necessarily in that order. Identify the currents corresponding to the four cases mentioned above.
State the importance of coherent sources in the phenomenon of interference.
Distinguish between an intrinsic semiconductor and P-type semiconductor. Give reason, why, a P-type semiconductor crystal is electrically neutral, although$\text{n}_{h}>>\text{n}_{e}$.
Two beams, one of red light and the other of blue light, of the same intensity are incident on a metallic surface to emit photoelectrons. Which one of the two beams emits electrons of greater kinetic energy?
An electric bulb marked 220V, 100W will get fused if it is made to consume 150W or more. What voltage fluctuation will the bulb withstand?
A block of mass 5.0kg slides down an incline of inclination 30° and length 10m. Find the work done by the force of gravity.
The electric current existing in a discharge tube is $2.0\mu\text{A}.$ How much charge is transferred across a cross-section of the tube in 5 minutes?
A staircase contains three steps each 10cm high and 20cm wide (figure). What should be the minimum horizontal velocity of a ball rolling off the uppermost plane so as to hit directly the lowest plane?
Taking force, length and time to be the fundamental quantities find the dimensions of:
  1. Density.
  2. Pressure.
  3. Momentum.
  4. Energy.
Explain the effect of dielectric on the capacitance of parallel plate capacitor and derive the equation of dielectric constant.