Page 35 - Physics - XI

6. Weight should be placed and removed only when beam is in rested position.
7. Weight should be added or removed by means of forceps only.

8. Final weighing should be obtained with doors of the balance closed.

Sources of Error
1. Some errors may be introduced due to the friction at the various parts of the balance.
2. The balance may have lower accuracy.

3. The weights used may not be standard.

VIVA VOCE

Q1. What is inertia?
Ans. The property of a body due to which the body continues in its state of rest or of uniform motion in
a straight line is called inertia.

Q2. What is the inertial mass of a body?
Ans. The mass of a body determined by using inertia as the basic property of matter is called inertial
mass. The inertial mass can be defi ned as the ratio of the force acting on a body to the acceleration
produced in it by the force.

Q3. How is inertial mass related to inertia?
Ans. The inertial mass is a measure of amount of inertia present in a body. Higher is the inertial mass,
higher is the inertia and vice-versa.
Q4. What is the mass of a body?
Ans. The quantity of matter possessed by a body is called mass.

Q5. What is S.I. and C.G.S. units of mass?
Ans. S.I. unit of mass is kilogram and C.G.S. unit of mass is gram.

Q6. What is the relation between S.I. and C.G.S. units of mass?
Ans. 1 kilogram = 1000 gram

Q7. What is the weight of a body?
Ans. Weight of a body is defi ned as the force with which the body is attracted by the Earth towards its
centre.

Q8. What is the diff erence between mass and weight?
Ans. (i) Mass of a body is constant at all the places, but weight of a body varies from place to place as
‘g’ changes from place to place.
(ii) Mass of a body cannot be zero, but weight of a body at the centre of the Earth is zero as g = 0
at the centre of the Earth.

Q9. What is gravitational mass of a body?
Ans. The gravitational mass can be defi ned as the mass which off ers gravitational force of attraction
towards the centre of the Earth.

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