Due to the high power of ultrasound waves, it is used for breaking and cutting objects. (T or F)

T/F Solder is used for welding electrical wires together.

A SONAR (sound navigation and ranging) uses ultrasonic waves to detect and locate objects under water. In a submarine equipped with a SONAR the time delay between generation of a probe wave and the reception of its echo after reflection from an enemy submarine is found to be 77.0 s. What is the distance of the enemy submarine? (Speed of sound in water = 1450 m s^-1 ).

How does the resolving power of a compound microscope change of decreasing the wave length of light used,and

In the following statements ,tick 'T' against those which are true and 'F' against those which are false. The number opf oscillations per second of a viberating object is called its time period. (T/F)

Show that a convex lens produces an N times magnified image,when the object distances from the lens have magnitude (f+- f//N) .Here,f is the magnitude of the focal length of the lens.Hene,find the two values of object distance,for which a convex lens of power 2.5 D will produce an image that is four times as large as the object.

A reflecting type telescope has a large spherical mirror for its objective with radus of curvature equal to 80 cm.What is the magnifying power of telescope,if eyepiece used has a focal length of 1.6 cm.

Calculate the resolving power of a telescope,whose objective lens has an aperture of 1.0 m for the wave-length of light 500 nm?