A screw gauge has 50 divisions on its circular scale and its screw moves by 1 mm on turning it by two rotations. When the flat end of the screw is in contact with the stud, the zero of circular scale lies below the base line and 4th division of circular scale is in line with the base line.

Find —

(i) the pitch,

(ii) the least count and

(iii) the zero error, of the screw gauge.

Figure below shows the reading obtained while measuring the diameter of a wire with a screw gauge. The screw advances by 1 division on main scale when circular head is rotated once.

Find —

(i) pitch of the screw gauge,

(ii) least count of the screw gauge, and

(iii) the diameter of the wire.

The pendulum used in a clock is:

1. Simple pendulum
2. Compound pendulum
3. Second pendulum
4. None of these

The effective length of a pendulum is related with time period as :

1. T² ∝ l²
2. T³ ∝ l
3. T² ∝ l
4. T ∝ L³