Choose the correct option: (i) Dry cells are less portable compared to Voltaic cells. (True/False) (ii) A coil becomes an electromagnet only when electric current flows through it. (True/False) (iii) An electromagnet, using a single cell, attracts more iron paper clips than the same electromagnet with a battery of 2 cells. (True/False)
False. Dry cells are more portable than Voltaic cells because they use a thick moist paste as electrolyte instead of liquid, making them easier to carry and use.
True. An electromagnet works only when electric current flows through the coil, as the magnetic field is produced by the electric current.
False. An electromagnet with a battery of 2 cells attracts more iron paper clips than one with a single cell because more cells provide larger current, creating a stronger magnetic field.
Explanation
(i) The chapter states that Voltaic cells contain liquid electrolyte in a glass or plastic container, which makes them less convenient for everyday use. Dry cells are called 'dry' because the electrolyte is not a liquid but a thick moist paste, making them one of the most widely used and portable electric cells. (ii) The chapter explains that when electric current flows through a conductor, it produces a magnetic field around it. When the current stops, this magnetic effect disappears. A current carrying coil that behaves as a magnet is called an electromagnet. (iii) The chapter states that a single cell provides only a small amount of current, so the magnetic field is weak. A battery with more cells gives a larger current, which creates a stronger magnetic field, so the coil can attract more clips.