Download App

Electromagnetic Waves — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsElectromagnetic Waves5 Marks
Question
Answer the following question:
If the earth did not have an atmosphere, would its average surface temperature be higher or lower than what it is now?
✓

Answer

In the absence of an atmosphere, there would be no greenhouse effect on the surface of the Earth. As a result, the temperature of the Earth would decrease rapidly, making it chilly and difficult for human survival.

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 "5 Marks Questions" from Electromagnetic Waves→Electromagnetic Waves — all question types→Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Consider the de Broglie wavelength of an electron and a proton. Which wavelength is smaller if the two particles have.
  1. The same speed.
  2. The same momentum.
  3. The same energy?.
→
A source emitting sound at frequency 4000Hz, is moving along the Y-axis with a speed of 22m/s. A listener is situated on the ground at the position (660m, 0). Find the frequency of the sound received by the listener at the instant the source the origin. Speed of sound in air = 330m/s.
→
A uniform chain of length L and mass M overhangs a horizontal table with its two third part on the table. The friction coefficient between the table and the chain is $\mu.$ Find the work done by the friction during the period the chain slips off the table.
→
Two identical pith balls are charged by rubbing against each other. They are suspended from a horizontal rod through two strings of length 20cm each, the separation between the suspension points being 5cm. In equilibrium, the separation between the balls is 3cm. Find the mass of each ball and the tension in the strings. The charge on each ball has a magnitude $2.0 \times 10^{-8}C.$
→
Find the maximum magnitude of the linear momentum of a photoelectron emitted when light of wavelength 400 run falls on a metal having work function 2.5eV.
→
$i.$ A Why does the electric field inside a dielectric slab decrease when kept in an external electric field?
$B.$ Derive an expression for the capacitance of a parallel plate capacitor filled with a medium of dielectric constant $K.$
$ii.$ A charge $q =2 \mu C$ is placed at the centre of a sphere of radius $20 \ cm $. What is the amount of work done in moving $4 \mu C$ from one point to another point on its surface?
$iii.$ Write a relation for polarisation $\overrightarrow{ P }$ of a dielectric material in the presence of an external electric field.
→
The circuit in Fig. shows two cells connected in opposition to each other. Cell $E_1$ is of emf 6V and internal resistance 2Ω; the cell $E_2$ is of emf 4V and internal resistance 8Ω. Find the potential difference between the points A and B.
→
A uniform rod of length L rests against a smooth roller as shown in figure. Find the friction coefficient between the ground and the lower end if the minimum angle that the rod can make with the horizontal is $\theta.$
→
A current i is passed through a silver strip of width d and area of cross-section A. The number of free electrons per unit volume is n.
  1. Find the drift velocity v of the electrons.
  2. If a magnetic field B exists in the region, as shown in the figure, what is the average magnetic force on the free electrons?
  3. Due to the magnetic force, the free electrons get accumulated on one side of the conductor along its length. This produces a transverse electric field in the conductor, which opposes the magnetic force on the electrons. Find the magnitude of the electric field which will stop further accumulation of electrons.
  4. What will be the potential difference developed across the width of the conductor due to the electron-accumulation? The appearance of a transverse emf, when a current-carrying wire is placed in a magnetic field, is called Hall effect.
→
Gautam went for a vacation to the village where his grandmother lived. His grandmother took him to watch ‘nautanki’ one evening. They noticed a blackbox connected to the mike lying nearby. Gautam’s grandmother did not know what that box was. When she asked this question to Gautam, he explained to her that it was an amplifier.
  1. Which values were displayed by the grandmother? How can inculcation of these values in students be promoted?
  2. What is the function of an amplifier?
  3. Which basic electronic device is used in the amplifier?
→