ICS Part 1 Physics English Medium Chapter 2 Online Short Questions Test with Answers

Question # 1

Ans 1: Physical Quantities:Those quantities which can be measured are known as physical quantities. For example, length, mass, temperature, speed, velocity, acceleration, energy , torque etc.
Magnitude:A number with proper unit is known as magnitude for example, 100 kg, 50 N, 1000 m etc.

Question # 2

Question # 3

Ans 1: We known that the torque depends upon the moments arm and applied force. Mathematically we have
T = r*F
As we have given that the gravitational force acting on a satellite is directed towards the centre of the earth. As for central force, the moment arm is zero r= 0 so T = o*F = 0
T= 0
Eq (2) shows that the torque produced by gravitational force acting on a satellite zero

Question # 4

Ans 1: The minimum number of unequal vector to result in to a null vector must be three. If we add three vector of unequal magnitude in such a way that they forms the sides of a triangle, then their resultant must be zero.
In the given figure three vectors A, B, and C are added according to head to tail rule and they form the side of a triangle. Now for getting their resultant, we will combine the tail of A with the head of C which already coincides each other. Thus we get a null vector or zero vector as a resultant
R= A+B+C = 0

Question # 5

Ans 1: No, the components of two vectors cannot be equal in magnitude if the two vector have unequal magnitudes.

Question # 6

Ans 1: A unit vector in a given direction is a vector with magnitudes one in that direction.Its is used to represent the direction of a vector.

Question # 7

Ans 1: No a body cannot rotate about its center of gravity under the action of its weight.Because the whole weight of the body acts on its center of gravity. The moment arm is zero in this case .

Question # 8

Ans 1: Concurrent Force:Two or more than two force are said to be concurrent force, If they are acting upon a body and their lines of action passes through a common point.Explanation:Consider a bulb which is suspended by means of a thread from a rigid support In this case the weight 'w' of the bulb is acting in down wards direction while the tension 'T' in the thread is acting of both forces passes through the same point or common point. Both forces balance each other and as a a result the bulb remain the state of equilibrium such force are know as concurrent forces.

Question # 9