InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Why is the metal box of the gold-leaf electroscope earthed? |
| Answer» During experiments with a gold-leaf electroscope, free charges exist on the outer surfaces of the tin (metallic) plates used in it. These free charges repel like charges on the leaves and decrease their divergence. Because of earthing of the electroscope, these free charges move to the ground. Hence the sensitivity of the device increases. | |
| 2. |
Why can one ignore quantisation of electric charge when dealing with macroscopic i.e., large scale charges? |
| Answer» The charge at macroscopic level is so large compared to the charge of an electron that quantisation of charge has no practical importance at this level. The charge of an electron is `1.6xx 10^(-19)`C which means that a small charge of `1muC` has about `10^(13)` electrons present in it. For such a large number of electrons there is no significance of quantisation and should be treated as continuous. | |
| 3. |
Diamond, ebonite, bakelite -these are ______ of electric ity. |
| Answer» Correct Answer - non- conductors | |
| 4. |
What should be the shape of a conductor to retain its charge? |
| Answer» Correct Answer - spherical | |
| 5. |
What kind of charges are produced at the near end and at the far end of a conductor due to induction? |
| Answer» Correct Answer - opposite, similar | |
| 6. |
If complete induction takes place, the amount of the inducing charge and that of the induced charge become _________ |
| Answer» Correct Answer - equal | |
| 7. |
In case of electrostatic induction there should be a __________ between the charged body and the uncharged body. |
| Answer» Correct Answer - gap | |
| 8. |
___________precedes attraction. |
| Answer» Correct Answer - induction | |
| 9. |
Which is the appropriate season for performing experi ments on statical electricity? |
| Answer» Correct Answer - winter | |
| 10. |
Where does the charge of a conductor reside? |
| Answer» Correct Answer - outer surface | |
| 11. |
Dry air is a good______ |
| Answer» Correct Answer - Insulator | |
| 12. |
The surface area of a body is `25 cm^2` and its surface density of charge is 5 CGS unit. What is the total charge on it? |
| Answer» Correct Answer - 125 CGS unit | |
| 13. |
The diameter of a sphere is 2 cm. The sphere is hollow and conducting and is given a charge of 6.16 units. Determine the surface density of charge of the sphere on its outer and inner surfaces in CGS unit. |
| Answer» Correct Answer - 0.49 CGS unit, 0 | |
| 14. |
What will be the surface density of charge of a sphere of radius 4 cm, if it is given 182 esu of charge? |
| Answer» Correct Answer - 0.9 esu . `cm^(-2)` | |
| 15. |
How much charge is to be given to a sphere of radius 30 cm so that its surface density of charge will be `2/pi` CGS unit? |
| Answer» Correct Answer - 7200 CGS unit | |
| 16. |
A conductor is charged with `14.4 xx 10^(-19)` C. Determine the number of deficit of electrons in it. What will be the change in mass of the conductor? |
| Answer» `9,81xx10^(-31)` kg mass (decrease) | |
| 17. |
To determine the nature of charge of a body it is brought ________ to a charged electroscope from a distance. |
| Answer» Correct Answer - slowly | |
| 18. |
Write the name of an insulator. |
| Answer» Correct Answer - Glass | |
| 19. |
Write the name of a good conductor. |
| Answer» Correct Answer - silver | |
| 20. |
If a body has `1.5 xx 10^7` number of excess electrons, what is the charge on the body? |
| Answer» Correct Answer - `-2.4xx10^(-12) C` | |
| 21. |
If `10^22` electrons are transferred from a metallic sphere, what will be the charge of the sphere? |
| Answer» 1600 C positive charge | |
| 22. |
A body has `-80muC` charge. What is the number of excess electrons in the body? |
| Answer» Correct Answer - `5xx10^14` | |
| 23. |
A positively charged glass rod attracts a light hanging body and thereafter repels it. The hanging body initially wasA. negatively chargedB. positively chargedC. unchargedD. earth-connected |
| Answer» Correct Answer - C | |
| 24. |
Charge resides only on the_______ of a conductor. |
| Answer» Correct Answer - outer surface | |
| 25. |
Five balls marked by numbers from 1 to 5 are hung by different threads. It is seen that the pairs of the balls (1,2), (2, 4), (4,1) attract each other. Again the pairs (2,3) and (4,5) repel each other. So the ball marked by 1 isA. positively chargedB. negatively chargedC. unchargedD. made by a metal |
| Answer» Correct Answer - C | |
| 26. |
`10^6` electrons are given to a pith ball. The charge of the ball will beA. `1.6xx10^(-13) C`B. `1.6xx10^(-19) C`C. `1.6xx10^(-25) ` CD. none of the above |
| Answer» Correct Answer - A | |
| 27. |
In case of a _________ conductor the surface density of charge is equal everywhere. |
| Answer» Correct Answer - spherical | |
| 28. |
If a cubical conductor be charged, where will the surface density of charge be maximum? |
| Answer» at eaach of the vertices of the cube | |
| 29. |
The charges of the clouds responsible for lightning are duced due toA. conversion of raindrops into electronsB. the electric field of the earthC. creation of ions by the sunD. friction among the water drops |
| Answer» Correct Answer - D | |
| 30. |
Greater is the _______ of a region of a conductor, _____ is the accumulation of charge at that region. |
| Answer» Correct Answer - curvature, greater | |
| 31. |
Is it safe or unsafe to remain inside a car at the time of lightning? |
| Answer» Correct Answer - safe | |
| 32. |
If a body is charged by rubbing, its weightA. does not chargeB. increase a littleC. decrease a littleD. may increase or decrease a little |
| Answer» Correct Answer - D | |
| 33. |
Two identical metallic spheres of the same mass are taken. Positive Q C charge is developed on one and an equal amount of negative charge is developed on the other. After chargingA. the two spheres will have equal massB. the sphere charged negatively will have a greater massC. the sphere charged positively will have a greater massD. the sphere charged negatively will have a smaller mass |
| Answer» Correct Answer - B | |
| 34. |
The ratio of the radii of two spheres is 5:2 and that of their charges is 5:3. Determine the ratio of the surface densities of charge of the two spheres. |
| Answer» Correct Answer - `4:15` | |