Q.1. Should the centre of mass of a body necessarily lie inside the body? Explain. Answer Answer: No, it may lie outside the body. In case of semicircular ring, it is at the centre which is outside the ring. Q.2. What physical quantities do the following represent?(a) Moment of linear momentum(b) Rate of change of … Read more
Q.1. A man raises a mass ‘m’ to a height ‘h’ and then shifts it horizontally by a length ‘x’. What is the work done against the force of gravity? Answer Answer: Work done against gravity is mgh, as no work is done in the horizontal displacement. Q.2. Name and define SI unit of work. … Read more
Q.1. State Newton’s first law of motion. Answer Answer: Everybody continues to be in state of rest or of uniform motion in a straight line unless compelled by some external force to act otherwise. Q.2. Two objects having different masses have same momentum. Which one of them will move faster. Answer Answer: Object with smaller … Read more
Q.1. Are rest and motion absolute or relative terms? Answer Answer: Yes, both rest and motion are relative terms. An object at rest in one frame of reference can be in motion in another frame of reference. Q.2. Can an object be at rest as well as in motion at the same time? Answer Answer: … Read more
Q.1. What do you mean by triple point ? Answer Answer: It is a particular point in the phase diagram, representing a particular pressure and temperature at which a substance can coexist in all three phases in solid, liquid and gas. Q.2. Why the triple point of water is considered as a standard fixed point … Read more
Q.1. Why do a spring balance show wrong measure after long use? Answer Answer: After long use the spring gradually loses its elastic nature and doesn’t come back to its initial configuration completely after the weight is withdrawn. Q.2. Which is more elastic water or air and why? Answer Answer: Water is more elastic than … Read more
Q.1. What type of mechanical wave exists in air and inside water? Answer Answer: Longitudinal waves exist in both air and inside the water. Q.2. What is the phase difference between the wave y = a cos(wt + kx) and y = a sin (wt + kx)? Answer Answer: Phase difference is 90° Q.3. What … Read more
Very Short Answer Type Questions [1 Mark Each] 1. Which of the following conditions is not sufficient for SHM and why? (a) Acceleration α displacement (b) Restoring force α displacement Answer Answer: Condition (a) is not sufficient as the direction of acceleration is opposite to displacement and that needs to be mentioned. 2. A particle … Read more
Very Short Answer Type Questions [1 Mark Each] Q.1. For ideal behavior of a gas, state the condition in terms of density of the gas. Answer Answer: For ideal gas, P = ρRT For ideal behavior, ρ should be low. Q.2. The velocities of three molecules A,B,C of a gas are 3V, 4V, and 5V … Read more
Very Short Answer Type Questions [1 Mark Each] Q.1. Is the heat supplied to a system always equal to the increase in its internal energy? Answer Answer: From 1st law of thermodynamics, dQ = dU + dW If dW = 0, then dQ = dU. i.e. if heat is supplied at constant volume so that … Read more
Very Short Answer Type Questions [1 Mark Each] Q.1. When a vessel containing a liquid is falling freely, does Archimedes’ principle hold good in it? Answer Answer: No – because in fall Buoyant force doesn’t exist. Q.2. A block of wood floats in a bucket of water in a lift. Will there be any change … Read more
