Answer:
YES
Explanation:
An echo may be defined as a sound which is repeated because of the sound waves that are produced are reflected back after striking a surface. Sound waves can smoothly bounce off the hard objects in the same manner as a rubber ball bounces back the ground.
When a sound wave strikes a hard surface, the sound waves gets reflected back and bounces back to the observer and produces an echo. If the sound waves strikes a soft surface it absorbs the sound.
Although the direction of a sound changes but the echo sounds in the same way as the original sound.
For all antinodal positions we know that

now we also know the relation between phase difference and path difference

now we will have

now from above equation we will have

now for the first anti node position
N = 1

Option D is correct
Answer:B
Explanation: an atom is the smallest particle of an element that can take part in a chemical reaction.
Answer:
E =230.4 MJ
Explanation:
As 1 mole of electron = 6X 10^23 particles.
charge of an electron is 1.6 X 10 ^-19 C
Finding Charge:
(6X10^23 ) (2.7)(1.6X10^-19 C)
i.e. 192 K C
now to find the energy released from electrons
V=E/q
E=V X q
i.e E = 120 V X 192 K C
E =230.4 MJ
Answer:
I2 = 3.076 A
Explanation:
In order to calculate the current in the second loop, you take into account that the magnitude of the magnetic field at the center of the ring is given by the following formula:
(1)
I: current in the wire
R: radius of the wire
μo: magnetic permeability of vacuum = 4π*10^-7 T/A
In the case of the two wires with opposite currents and different radius, but in the same plane, you have that the magnitude of the magnetic field at the center of the rings is:
(2)
I1: current of the first ring = 8A
R1: radius of the first ring = 0.078m
I2: current of the second ring = ?
R2: radius of the first second = 0.03m
To find the values of the current of the second ring, which makes the magnitude of the magnetic field equal to zero, you solve the equation (2) for I2:

The current of the second ring is 3.076A and makes that the magntiude of the total magnetic field generated for both rings is equal to zero.