Revise all concepts, definitions, laws,

formulae and units

Tables of 1 to 30 squares and square

roots of 1 to 30 cubes of 1 to 10

Questions of Deep Knowledge

1 Which of the following quantities have unit, but not the dimensions.

(a) dielectric constant

(b) coefficient of viscosity

(c) plane angle

(d) refractive index

2. A block of mass 10kg is resting on a horizontal surface. A force of 50N is applied on it. If coefficient of friction between the block and the surface is 0.6. what will be the force of friction? (g = 10 m/s2)

(a) Zero

(b) 50 N

(c) 60 N

(d) 40 N

CORRECT OPTION IS

(b) 50 N

fs = mgμ

fs = 10×10×0.6

fs = 60N

But applied force is 50N.

Hence, the block will not move.

Questions of Presence of mind

1. Three tuning forks of frequencies 400 H2, 401 Hz and 402 Hz are

sounded together. How many beats will be heard?

(a) 3

(b) 5

(c) 6

(d)1

2. Three tuning forks of frequencies 400Hz, 401Hz and 402H2 are

sounded together. How many beats will be produced?

(a) 3

(b) 5

(c) 6

(d)1

Solution:

g

Rcos

R cos

g

R cos2

g

1 g

2 R cos

3. A hemispherical bowl of radius R is revolved around its vertical axis. A Light weight sphere in it also revolves in it, without sliping. The radius of the hemispherical passing through the sphere makes angle θ with the axis of rotation. The angular velocity of the sphere is:

(a) (b)

(c) (d)

Solution:Motion of the sphere is like motion of conical pendulum.Hence R cos

T 2g

2but T

2 R cos2  

g

g       

R cos

Questions on application mind

1.Charge q moves around charge Q in circular path. The work done by charge Q on q is

(a) (b)

(c) Zero (d)

20

1 Qq

4 k r 0

1 q

4 k r

20

1 Qq2 r

4 k r

Solution: Charge q is moving over an equipotential surface Hence, work done is zero.

2. Time taken by radio waves to go come back from communication satellite is nearly

(a) 1s (b)

(c) (d) 4s

1s

4

1s

8

Height of communication satellite above the surface of the earth is 36000 km.

∴ Distance travelled by radio waves = 72000 km

Velocity of radio waves = 3 × 108 m/s

8

6

6

72000kmtime

3 10 m / s

72 10 1time

300 10 4

Full Portion Tests

Time Table

Time Allotment

Mistakes

Confidence

Thank

you ...!