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JEE PHYSICS MCQ: CURRENT ELECTRICITY
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The Earth's surface has a negative surface charge density of . The potential difference of between the top of the atmosphere and the surface, results (due to low conductivity of the lower atmosphere) in a current of only over the entire globe. If there is no mechanism of sustaining atmospheric electric field, how much time (in sec) would be required to neutralize the Earth's surface? Radius of earth
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Correct option: D
283
Option B () is correct because it is calculated by using the formula for the velocity of sound in a gas and taking the ratio for hydrogen and helium.
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Statement-2: For most of the resistors, resistance increases with increase in temperature. The reciprocal of resistance is Corresponding to the resistance , which is order of colour coding on carbon resistors? In a meter bridge, the gaps are closed by resistance 2 and 3 ohms. The value of shunt to be added to 3 ohm resistor to shift the balancing point by is
Statement-2: For most of the resistors, resistance increases with increase in temperature. The reciprocal of resistance is Corresponding to the resistance , which is order of colour coding on carbon resistors? In a meter bridge, the gaps are closed by resistance 2 and 3 ohms. The value of shunt to be added to 3 ohm resistor to shift the balancing point by is