Asa transverse wave strikes against a fixed end ……. 

(a) its phase changes by 180° , but velocity does not change.

(b) its phase does not change, but velocity changes 

(c) its velocity changes and phase too changes by 180°

(d) nothing can be predicted about changes in its velocity and phase

Choose the correct one.

If ΔABC and ΔDBC are on the same base BC, AB = DC and AC = DB (Fig. 6.21),then which of the following gives a congruence relationship?

(a) ΔABC ≅ ΔDBC (b) ΔABC ≅ ΔCBD

(c) ΔABC ≅ ΔDCB (d) ΔABC ≅ ΔBCD

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