(A). 200 Hz (B). 3000 Hz (C). 120 Hz (D). 600 Hz

(A). $$0$$ (B). $${pi}/{2}$$ (C). $$pi$$ (D). $$dfrac{pi}{4}$$

(A). $$(x-vt)^{2}$$ (B). $$log (x+vt)$$ (C). $$e^{-(x-vt)^{2}}$$ (D). $$dfrac{1}{x+vt}$$

(A). 3 (B). 4 (C). 5 (D). 7

(A). $$2 times 10^6 m$$ (B). $$3 times 10^6 m$$ (C). $$4 times 10^6 m$$ (D). $$5 times 10^6 m$$

(A). speed – decreases ; wavelength – decreases (B). speed – decreases ; wavelength – remains constant (C). speed – remains constant ; wavelength – decreases (D). speed – remains constant ; wavelength – remains constant

(A). 3 cm (B). 100 cm (C). 5 cm (D). 2 cm

(A). A (B). zero (C). 2 A (D). 3 A

(A). $$9 times 10^{13} cycles/sec$$ (B). $$ 10^{15} cycles/sec$$ (C). $$90 cycles/sec$$ (D). $$3000 cycles/sec$$