Terminal PD of a cell of emf 4 V is zero when current from it is 10 A. Internal resistance of the cell is |

A) 0.1 Ω | B) 0.2 Ω | C) 0.4 Ω | D) 1 Ω |

Terminal PD of a cell is 5 V when 2A of current is drawn from it and 8V when current of 4A is used to charge it. Internal resistance resistance of the cell is |

A) 0.1 Ω | B) 0.2 Ω | C) 0.5 Ω | D) 1 Ω |

Two cells of equal emfs but different internal resistances of $r_1$ and $r_2$ are connected in series . An external resistance $R$ is connected in series with two sources of e.m.f. |

A) $R = (r_1-r_2)$, for terminal potential difference to be zero across source 1. |

B) $R = √{r_1r_2}$, for terminal potential difference to be zero across both sources. |

C) $R = r_2^2/r_1$, for terminal potential difference to be zero across source 2. |

D) $R = r_1^2/r_2$, for terminal potential difference to be zero across source 1. |

Maximum power a cell of emf E and internal resistance r can provide any external resistance is | |||

A) $E^2/r$ | B) $E^2/2r$ | C) $E^2/3r$ | D) $E^2/4r$ |

Current from a cell of emf 4V and internal resistance 0.1 Ω, when 30 W power is delivered to an external resistance is | |||

A) 10 A | B) 30 A | C) Both | D) None |

3,3,1,4,3