Discussion
Home ‣ General Knowledge ‣ Physics Comments
- Question
Hydrogen atom is excited from ground state to another state with principal quantum number equal to 4. Then the number of spectral lines in the emission spectra will be
Options- A. 2
- B. 6
- C. 5
- D. 3
- Correct Answer
- 6
ExplanationNumber of spectral lines from a state n to ground state is
n(n-1)/2 = 6
- 1. Water kept in an earthen pot is less cool on rainy days than in summer because during the rainy days
Options- A. the pores in the pot are closed
- B. rain water stops oozing out from the pores
- C. the water that oozes out does not evaporate quickely because of the large percent age of moisture in the air
- D. surface of the pot becomes damp Discuss
- 2. As the object covers equal distances in equal intervals of time, it is said to be in ____________ motion.
Options- A. uniform
- B. linear
- C. translational
- D. equilibrium Discuss
- 3. Brightness of bulb depends on voltage or current?
Options- A. Current
- B. Voltage
- C. Both A & B
- D. None Discuss
- 4. Reading of a barometer going down is an indication of
Options- A. Storm
- B. Rainfall
- C. Snow
- D. Intense heat Discuss
- 5. Fog is an example of a
Options- A. liquid dispersed in gas
- B. solid dispersed in liquid
- C. liquid dispersed in solid
- D. gas dispersed in liquid Discuss
- 6. When an electric bulb breaks , there is an explosive sound. That is due to
Options- A. the chemical reaction between the gases inside the bulb
- B. the compressed gases inside rushing out suddenly
- C. the air outside rushing in to fill the vacuum inside the bulb
- D. None of these Discuss
- 7. Energy is continuously generated in the sun due to
Options- A. Nuclear fusion
- B. Nuclear fission
- C. Radioactivity
- D. Artificial radioactivity Discuss
- 8. Rolling friction is caused by ____ from the following?
Options- A. Non-elastic effects
- B. Gravity
- C. Power dissipation
- D. Buoyancy Discuss
- 9. On the Kelvin scale ,the melting point of ice is
Options- A. 373K
- B. 100K
- C. 273K
- D. 0 K Discuss
- 10. The wavelength of a wave is the distance between
Options- A. Crest and Trough
- B. Crest and Crest
- C. Trough and Trough
- D. Both B & C Discuss
Physics problems
Search Results
Correct Answer: the water that oozes out does not evaporate quickely because of the large percent age of moisture in the air
Explanation:
To evaporate the water that oozes out, heat is required. Part of this heat is taken from the water inside which therefore become cool. Therefore (C) is correct. Here evaporation is less, so cooling too is less.
Correct Answer: uniform
Correct Answer: Both A & B
Explanation:
Brightness of bulb depends on both voltage and current. The brightness depends on power.
Since we know that Power (P) = Voltage x Current = V I
So whether you increase the current or the voltage the brightness will increase.
Example Illustration:
If you connect a long bulb and a round bulb in series, the long bulb glows but the round bulb does not. Both of them have the same current flowing through them (they are in series) but the long bulb has a greater voltage across it because it has more resistance (even though V= IR is not obeyed exactly, voltage drop does depend on the resistance). If you connect a round bulb and a long bulb in parallel, however, it is the round bulb that is brighter because now the voltage across both bulbs is the same but the current is larger through the round bulb (smaller resistance).
Hence, the brightness of a bulb depends on power i.e, both voltage and current.
Correct Answer: Rainfall
Explanation:
Barometer is instrument which is used to measure to pressure. A slow downfall of reading suggests a low pressure area is passing in a nearby region, it may rains. If the reading is going down very fast then its an indication of storm (within 5-6 hours).
Correct Answer: liquid dispersed in gas
Correct Answer: the air outside rushing in to fill the vacuum inside the bulb
Explanation:
The inside of the bulb being a vacuum, the outside air rushes in when the bulb is broken. The vibrations of the rushing air molecules produce the sound.
Correct Answer: Nuclear fusion
Correct Answer: Non-elastic effects
Explanation:
Rolling friction or rolling drag is the force resisting the motion when a body rolls on a surface. It is mainly caused by non-elastic effects, that is, not all the energy needed for deformation of the wheel, roadbed, etc... is recovered when the pressure is removed.
Another cause of rolling resistance lies in the slippage between the wheel and the surface, which dissipates energy.
Correct Answer: 273K
Correct Answer: Both B & C
Explanation:
Distance between two Consecutive Crests or two Consecutive Troughs is called Wavelength. But the distance between crest and adjacent trough is half the wavelength.
That is the distance between adjacent crest and trough is called Half the wavelength.
Comments
There are no comments.More in General Knowledge:
Programming
Copyright ©CuriousTab. All rights reserved.