Which of the following statements are correct?
(A) The emf of a cell depends on the internal resistance of the cell.
(B) The emf of a cell depends on the external resistance of the circuit.
(C) It is easier to start a car engine on a warm day than on a cold day.
(D) The temperature coefficient of resistance ($α$) of carbon is negative.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (C) and (D) only
Analysis of statements:
(A) The emf of a cell depends on the internal resistance of the cell → False. EMF is determined by chemical composition, not internal resistance.
(B) The emf of a cell depends on the external resistance of the circuit → False. EMF is independent of external resistance.
(C) It is easier to start a car engine on a warm day than on a cold day → True. Battery performance and fuel vaporization are better at higher temperatures.
(D) The temperature coefficient of resistance (α) of carbon is negative → True. Carbon is a negative temperature coefficient (NTC) material.
Correct Statements: (C) and (D)