Dimensional analysis

Question 1

1ly = ?

Answer 1

9.46 * 10^15 m

Question 2

1AU = ?

dist between sun and earth

Answer 2

1.5 * 10^11 m

Question 3

1 parsec = ?

Answer 3

The distance at which avg radius of earths orbit subtends arc of angle 1sec

Question 4

Principle of mass spectrograph

Answer 4

radius of trajectory directly proportional to mass

Question 5

No of si fi in 0.002308

Answer 5

4

Question 6

No of si fi in 123000

Answer 6

3

Question 7

No of si fi in 3.500

Answer 7

4

Question 8

Rule for multi/div of si fi

Answer 8

No of si fi should be equal to that having the least si fi

Question 9

Rule for add/sub of si fi

Answer 9

No of decimal places should be equal to that of number having least decimal places

Question 10

LC of vernier

Answer 10

MSD - VSD

Question 11

LC of screw gauge

Answer 11

Pitch/no of div on circular scale

where pitch = dist travelled per rotation of screw

Question 12

Reading of vernier

Answer 12

N + n(LC)
N = last div that can be seen on main scale
n = div on vernier scale that coincides with any of the main scale reading

Question 13

Zero error of vernier when +ve when -ve

Answer 13

+ve when zero of vernier ahead of zero of main scale

-ve when zero of vernier behind zero of main scale

Question 14

+ve zero error calculation

Answer 14

Zero error = N + n(LC)

then subtract it

Question 15

-ve zero error calculation

Answer 15

n(LC)
n should be counted from back
then add it

Question 16

f = nv/2l f= v(2n+1)/4l

What is the correction

Answer 16

f = nv/(2l + 2.4r) f = (2n+1)v/(4l + 2.4r)