The maximum power drawn out of the cell from a source is given by (where $r$ is internal resistance)
The maximum power drawn out of the cell from a source is given by (where $r$ is internal resistance)
- A
${E^2}/2r$
- B
${E^2}/4r$
- C
${E^2}/r$
- D
${E^2}/3r$
Similar Questions
The brightness of a bulb will be reduced, if a resistance is connected in
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Assertion : When current through a bulb decreases by $0.5\%$, the glow of bulb decreases by $1\%$.
Reason : Glow (Power) which is directly proportional to square of current.
Assertion : When current through a bulb decreases by $0.5\%$, the glow of bulb decreases by $1\%$.
Reason : Glow (Power) which is directly proportional to square of current.
- [AIIMS 2015]
A heating coil can heat the water of a vessel from $20\,^oC$ to $60\,^oC$ in $30$ minutes. Two such heating coils are put in series and then used to heat the same amount of water through the same temperature range. The time taken now will be ............ $min$ (neglecting thermal capacity of the coils)
A heating coil can heat the water of a vessel from $20\,^oC$ to $60\,^oC$ in $30$ minutes. Two such heating coils are put in series and then used to heat the same amount of water through the same temperature range. The time taken now will be ............ $min$ (neglecting thermal capacity of the coils)
The electric current passing through a metallic wire produces heat because of
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