Ch 1 ( SHM And Waves)

Question 1

Vibrating body

Answer 1

A body is said to be viberating if it moves back and forth or to and fro about a mean position
Eg simple pendulum motion

Question 2

Spring constant from hookes law

Answer 2

According to hookes’ law, the force applied on the spring is directly proportional to the change in length of the spring.
F= -kx
K= -f/x
K is called the spring constant

Question 3

Restoring force

Answer 3

The force that always pushes or pulls the viberating body towards mean position

Question 4

SHM

Answer 4

Simple harmonic motion occurs when the net force is directly proportional to the displacement from mean position, and acceleration is always directed towards mean position.

Question 5

Characters of SHM

Answer 5

1. The body viberates about a fixed position
2. Acceleration is directed towards mean position
3. Magnitude of acceleration is always directly proportional to the displacement from mean position, i.e., acceleration will be 0 at mean and maximum at extreme position
4. Velocity is maximum at mean and 0 at extrem position

Question 6

One viberation

Answer 6

One complete round trip of a viberating body about its mean position

Question 7

Time period

Answer 7

Time taken by a viberating body to complete one viberation

Question 8

Frequency

Answer 8

No. Of viberations or cycles if a viberation body in one second
Unit = hertz ( Hz )

Question 9

Formula for frequency and time period

Answer 9

F = 1/T

Question 10

Time period of pendulum formula

Answer 10

T=2pi under root l/g

Question 11

Time period of mass spring system formula

Answer 11

T= 2pi under root m/g

Question 12

Amplitude

Answer 12

The maximum displacement of a viberating body on either side from its mean position
Unit= m

Question 13

No. Of times, the human ear drum can oscillate

Answer 13

20,000 times in one second

Question 14

Damped oscillation

Answer 14

Oscillation in the presence of some resistive force

Question 15

Wave

Answer 15

A wave is a disturbance in the medium that causes the particles of the medium to undergo viberatory motion about their mean position in equal interval of time

Question 16

Types of waves

Answer 16

Mechanical waves
Electromagnetic waves

Question 17

Mechanical waves

Answer 17

Waves that require a medium for their propogation
Eg water waves and sound waves

Question 18

Electromagnetic waves

Answer 18

Waves which do not require a medium for their propogation
Eg heat and light waves

Question 19

Types of mechanical waves

Answer 19

Longitudal waves
Transverse waves

Question 20

Longitudal waves

Answer 20

In lonitudal waves, the particles of medium move back and forth along the direction of propogation of the wave
Eg sound waves

Question 21

Transverse waves

Answer 21

The particles of the medium move perpendicular to the direction of propogation of the wave

Eg water waves

Question 22

Ripple tank

Answer 22

A device used to produce water waves and study their characteristics

Question 23

Reflection of wave

Answer 23

When a wave moving in one medium falls on the surface of another medium, they bounce back into 1st medium such that the angle of incidence is equal to the angle of reflection

Question 24

Refraction of wave

Answer 24

When a wave from one medium enters into another medium at some angle, its direction of travel changes

Question 25

Diffraction of wave

Answer 25

Bending or spreading of waves around sharp edges or corners of obstacles or slits