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17 questions · self-marked practice — reveal the answer and mark yourself.

Question 11 Mark
Read each statement below carefully and state, with reasons and examples, if it is true or false: A scalar quantity is one that Is conserved in a process.
Answer
False. Explanation: Despite being a scalar quantity, energy is not conserved in inelastic collisions.
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Question 21 Mark
Read each statement below carefully and state, with reasons and examples, if it is true or false: A scalar quantity is one that Must be dimensionless.
Answer
False. Explanation: Total path length is a scalar quantity. Yet it has the dimension of length.
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Question 31 Mark
Read each statement below carefully and state, with reasons, if it is true or false: The velocity vector of a particle at a point is always along the tangent to the path of the particle at that point.
Answer
True.Explanation:
because while leaving the circular path, the particle moves tangentially to the circular path.
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Question 41 Mark
Read each statement below carefully and state with reasons, if it is true or false: The total path length is always equal to the magnitude of the displacement vector of a particle.
Answer
False. Explanation: Total path length is a scalar quantity, whereas displacement is a vector quantity. Hence, the total path length is always greater than the magnitude of displacement. It becomes equal to the magnitude of displacement only when a particle is moving in a straight line.
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Question 51 Mark
Read each statement below carefully and state with reasons, if it is true or false: Three vectors not lying in a plane can never add up to give a null vector.
Answer
True. Explanation: Three vectors, which do not lie in a plane, cannot be represented by the sides of a triangle taken in the same order.
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Question 61 Mark
Read each statement below carefully and state, with reasons, if it is true or false: The net acceleration of a particle in circular motion is always along the radius of the circle towards the centre.
Answer
False. Explanation: The net acceleration of a particle is towards the centre only in case of a uniform circular motion.
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Question 71 Mark
For any arbitrary motion in space, which of the following relations are true: $\text{v}(\text{t})=\text{v}(0)+\text{a t}$ (The ‘average’ stands for average of the quantity over the time interval $t_1$ to $t_2$)
Answer
False. Explanation: The motion of the particle is arbitrary. The acceleration of the particle may also be non-uniform. Hence, this equation cannot represent the motion of the particle in space.
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Question 81 Mark
Read each statement below carefully and state, with reasons, if it is true or false: The acceleration vector of a particle in uniform circular motion averaged over one cycle is a null vector.
Answer
True.Explanation:
The direction of acceleration vector in a uniform circular motion is directed towards the centre of circular path. It is constantly changing with time. The resultant of all these vectors will be zero vector.
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Question 91 Mark
Read each statement below carefully and state, with reasons and examples, if it is true or false:A scalar quantity is one that
Does not vary from one point to another in space.
Answer
False. Explanation: A scalar quantity such as gravitational potential can vary from one point to another in space.
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Question 101 Mark
For any arbitrary motion in space, which of the following relations are true: $\text{v}_\text{average}=\frac{1}{2}(\text{v}(\text{t}_1)+\text{v}(\text{t}_2))$ (The ‘average’ stands for average of the quantity over the time interval $t_1$ to $t_2$)
Answer
False. Explanation: It is given that the motion of the particle is arbitrary. Therefore, the average velocity of the particle cannot be given by this equation.
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Question 111 Mark
Read each statement below carefully and state with reasons, if it is true or false: The average speed of a particle (defined as total path length divided by the time taken to cover the path) is either greater or equal to the magnitude of average velocity of the particle over the same interval of time.
Answer
True. Explanation: It is because of the fact that the total path length is always greater than or equal to the magnitude of displacement of a particle.
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Question 121 Mark
Read each statement below carefully and state with reasons, if it is true or false: The magnitude of a vector is always a scalar,
Answer
True. Explanation: The magnitude of a vector is a number. Hence, it is a scalar.
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Question 131 Mark
Read each statement below carefully and state with reasons, if it is true or false: Each component of a vector is always a scalar,
Answer
False. Explanation: Each component of a vector is also a vector.
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Question 141 Mark
For any arbitrary motion in space, which of the following relations are true: $\text{v}_{\text{average}}=\frac{[\text{r}(\text{t}_2)-\text{r}(\text{t}_1)]}{(\text{t}_2-\text{t}_1)}$ (The ‘average’ stands for average of the quantity over the time interval $t_1$ to $t_2$)
Answer
True. Explanation: The arbitrary motion of the particle can be represented by ythis equation.
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Question 151 Mark
For any arbitrary motion in space, which of the following relations are true: $\text{v}(\text{t})=\text{r}(0)+\text{v}(0)\text{t}+\frac{1}{2}\text{a t}^2$ (The ‘average’ stands for average of the quantity over the time interval $t_1$ to $t_2$)
Answer
False. Explanation: The motion of the particle is arbitrary; acceleration of the particle may also be non-uniform. Hence, this equation cannot represent the motion of particle in space.
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Question 161 Mark
Read each statement below carefully and state, with reasons and examples, if it is true or false: A scalar quantity is one that Can never take negative values.
Answer
False. Explanation: Despite being a scalar quantity, temperature can take negative values.
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Question 171 Mark
Read each statement below carefully and state, with reasons and examples, if it is true or false:A scalar quantity is one that
Has the same value for observers with different orientations of axes.
Answer
True. Explanation: The value of a scalar does not vary for observers with different orientations of axes.
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