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प्रश्न
A metal sphere is kept on an insulting stands. A negatively charged rod is brought near it, then the sphere is earthed as shown. On removing the earthing, and taking the negatively charged rod away, what will be the nature of charge on the sphere? Give reason for your answer.
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उत्तर १
There will be positive charge on the sphere.
Reason :
Negatively charged rod will induce positive charge on the sphere and negative charge well move in ground from other end.
उत्तर २
When we bring a negatively charged rod near the metal sphere, the free electrons in the sphere move away due to repulsion force and start piling up at the other end. The rear end becomes positively charged due to the deficit of electrons. After connecting the sphere to the ground, the electrons flow to the ground while the positive charges at the rear end remain as it is due to the attractive force of the negative charges on the rod. When the sphere is disconnected from the ground and the charged rod is removed, the positive charge spreads uniformly over the sphere as shown in the Figure below:
संबंधित प्रश्न
If the potential difference across the ends of a conductor is 220 V and the resistance of the conductor is 44 Ω (ohm), then the current flowing through is _________.
- 0.2 A
- 0.5 A
- 2 A
- 5 A
What will be the change in the current if the potential difference is kept constant and the resistance of the circuit is made four times?
- It will remain unchanged.
- It will become four times.
- It will become one-fourth.
- It will become half.
The relationship between the potential difference and the current in a conductor is stated in the form of a law.
1) Name the law.
2) What does the slope of V-I graph for a conductor represent?
3) Name the material used for making the connecting wire.
The unit of electrical resistance is:
(a) ampere
(b) volt
(c) coulomb
(d) ohm
Answer the following question.
Distinguish between Ohmic and non-ohmic substances; explain with the help of example.
The ratio of the potential difference to the current is known as ________.
Define Current density.
Define temperature coefficient of resistance.
Consider a current carrying wire (current I) in the shape of a circle. Note that as the current progresses along the wire, the direction of j (current density) changes in an exact manner, while the current I remain unaffected. The agent that is essentially responsible for is ______.
The circuit depicted in the figure is employed for studying Ohm’s Law. Instead of using a standard resistor, a student opts for a glass tube filled with mercury (tube 1), connected to the circuit through two electrodes, E1 and E2. He records the readings of the ammeter and voltmeter, thereby calculating the resistance. The student repeats the experiment by substituting tube 1 with tube 2, where the same amount of mercury fills tube 2.
Neglecting internal resistance of the cell use (> or < or =) to compare:
- the resistance in both the cases.
- the voltmeter readings in both the cases.
- the specific resistance in both the cases.
