(a) Which characteristic of sound is affected due to the larger surface of a school bell?

(b) Calculate the distance covered by the Ultrasonic wave having a velocity of 1.5 kms^-1 in 14 s, when it is received after reflection by the receiver of the SONAR.

(a) Complete the following nuclear changes:

²³⁸₉₂P ⟶ Q + ⁴₂He ⟶ R + ⁰_-1e

(b) Name the nuclear radiation which has the highest ionizing power.

A block and tackle system of pulleys has velocity ratio 4.

(a) Draw a labelled diagram of the system indicating clearly, the direction of the load and the effort.

(b) What is the value of the mechanical advantage of the given pulley system if it is an ideal pulley system?

A metre scale of weight 50 gf can be balanced at 40 cm mark without any weight suspended on it.

(a) If this ruler is cut at its centre then state which part [0 to 50 cm or 50 to 100 cm] of the ruler will weigh more than 25 gf.

(b) What minimum weight placed on this metre ruler can balance this ruler when it is pivoted at its centre?