Reflection from a Fixed End

Q. A wave travels on a light string. The equation of the wave is $y=Asin(kx+wt+{30}^{\circ }+{180}^{\circ })$, it is reflected from a heavy string tied to an end of the light string at x= 0. If 64% of the incident energy is reflected then what is the equation of the reflected wave?

1. $y=Asin(kx-wt+{30}^{\circ })$
2. $y=Asin(kx+wt+{30}^{\circ })$
3. $y=0.8Asin(kx-wt+{30}^{\circ })$
4. $y=0.8Asin(kx+wt+{30}^{\circ })$

Q. A wave travels on a light string. The equation of the wave is $y=Asin(kx+wt+{30}^{\circ }+{180}^{\circ })$, it is reflected from a heavy string tied to an end of the light string at x= 0. If 64% of the incident energy is reflected then what is the equation of the reflected wave?

1. $y=Asin(kx-wt+{30}^{\circ })$
2. $y=Asin(kx+wt+{30}^{\circ })$
3. $y=0.8Asin(kx-wt+{30}^{\circ })$
4. $y=0.8Asin(kx+wt+{30}^{\circ })$

Q. A wave travels on a light string. The equation of the wave is $y=Asin(kx+wt+{30}^{\circ }+{180}^{\circ })$, it is reflected from a heavy string tied to an end of the light string at x= 0. If 64% of the incident energy is reflected then what is the equation of the reflected wave?

1. $y=Asin(kx-wt+{30}^{\circ })$
2. $y=Asin(kx+wt+{30}^{\circ })$
3. $y=0.8Asin(kx-wt+{30}^{\circ })$
4. $y=0.8Asin(kx+wt+{30}^{\circ })$

Q. A string of length $40\text{cm}$ and linear mass density $0.80\text{g/cm}$ is fixed at both ends and kept under a tension of $32\text{N}$. A wave pulse is produced near one of the ends at $t=0$, as shown in the figure, which makes periodic motion between the ends. What is the time after which the string will have the same shape shown in the figure?

1. After $0.03\text{sec}$
2. After $0.06\text{sec}$
3. After $0.05\text{sec}$
4. After $0.04\text{sec}$

Q. $P$ is the junction of two wires $\text{A}$ and $\text{B}$. $\text{B}$ is made of steel and is thicker, while $\text{A}$ is made of aluminum and is thinner as shown in the figure$(i.e.{\mu }_B>{\mu }_A)$. If a wave pulse as shown in the figure approaches $P$, the reflected and transmitted waves from $P$ are respectively:

1. 
2. 
3. 
4.