1. (c) A is true but R is false
Assertion (A) is true: Copper ions migrate from the anode to the cathode during electrorefining of copper. In electrorefining, an impure copper anode is placed in an electrolyte solution of copper sulfate and sulfuric acid. A pure copper cathode is placed on the opposite side of the cell.
2. (a) Both A and R are true, and R is the correct explanation of A.
Assertion (A) is true: A lot of difference in the concentrations of ions was observed by a scientist between the fluid in the xylem cells of roots and that of the soil. Xylem cells actively take up ions from the soil, creating a concentration gradient that drives water into the roots by osmosis. This process is called active transport, and it requires energy from ATP.
Reason (R) is true: Xylem cells in the roots of plants which come in contact with the soil actively take up ions. This is because xylem cells have specialized proteins in their cell membranes that can transport ions against a concentration gradient.
3. (b) Both A and R are true, but R is not the correct explanation of A.
Both Assertion (A) and Reason (R) are true, but reason (R) is not the correct explanation of assertion (A). The current rating of a circuit is determined by the amount of current that the wires and other components in the circuit can safely handle. It is not determined by the type of appliances that are connected to the circuit.
4. (a) Both A and R are true, and R is the correct explanation of A.
Assertion (A) is true: All kitchen waste cannot form compost. For example, meat, fat, and dairy products can attract pests and diseases, and can also make the compost smell bad. Additionally, some food packaging materials, such as plastic and milk packets, are not biodegradable and cannot be composted.
Reason (R) is also true: Material like milk packets may not be biodegradable. Milk packets are typically made of a combination of paper, plastic, and aluminum. While the paper component is biodegradable, the plastic and aluminum components are not.
