MODEL ACTIVITY TASK CLASS – IX PHYSICAL SCIENCE - 1. Choose the correct answer : 1 x 3 = 3 1.1 The unit of the force constant of a spring is — (a) Nm (b) Nm(c) N/m2 (d) N/m. 1.2 The oxide of nitrogen that is formed when copper is treated with hot and concentrated nitric acid is- (a) NO (b) NO (C) NO (d) NO 1.3 A ball is thrown vertically upwards. At the highest point of the vertical path the ball will have (a) the greatest kinetic energy (b) the greatest potential energy (c) equal kinetic and potential energies (d) a potential energy that is smaller than its kinetic energy. 2. Determine whether the following statements are true or false : 1x3 2.1 When the reading of a barometer decreases rapidly, it indicates that a depression has formed 2.2 A solution that turns methyl orange yellow has a pH> 7. 2.3 Work is a vector quantity. Answer in brief: 2x 3.1 Explain the main difference between dissolution of the ions of sodium chloride in water and diss of a protein molecule in water.
Answers
The answers to the given questions are as follows:
1.1). The unit of the force constant of a spring is - N/m, (d).
1.2). The oxide of nitrogen that is formed when copper is treated with hot and concentrated nitric acid is - NO, (a).
1.3). A ball is thrown vertically upwards. At the highest point of the vertical path, the ball will have - potential energy that is smaller than its kinetic energy, (d).
2.1). When the reading of a barometer decreases rapidly, it indicates that a depression has formed. - True.
2.2). A solution that turns methyl orange to yellow has a pH> 7. - True.
2.3). Work is a vector quantity. - False.
3.1). The main difference between the dissolution of the ions of sodium chloride in water and the dissolution of a protein molecule in water is that sodium chloride conducts electricity but protein solution cannot conduct electricity.