Answer:
d. The length of the string is equal to one-half of a wavelength
Explanation:
A stretched string of length L, fixed at both ends, is vibrating in its third harmonic. How far from the end of the string can the blade of a screwdriver be placed against the string without disturbing the amplitude of the vibration
a. The length of the sting is equal to one-quarter of a wavelength.b. The length of the string is equal to the wavelength.c. The length of the string is equal to twice the wavelength.d. The length of the string is equal to one-half of a wavelength
e. The length of the string is equal to four times the wavelength
A stretched string of length L fixed at both ends is vibrating in its third harmonic H
How far from the end of the string can the blade of a screwdriver be placed against the string without disturbing the amplitude of the vibration
d. The length of the string is equal to one-half of a wavelength
There are two points during vibration , the node and the antinode
the node is the point where the amplitude is zero.
from the third harmonics, there are two nodes. The first node is half of the wavelength which is the closest to the fixed point.
for third harmonics=3/2lamda
Answer:
The net magnetic flux through the rest of Earth's surface is 
Explanation:
Given that,
Magnetic field = 42 μT
Area 

We need to calculate the flux per unit area

We need to calculate the total earth's surface area



We need to calculate the rest of earth's area

Put the value into the formula


We need to calculate the net magnetic flux through the rest of Earth's surface


Hence, The net magnetic flux through the rest of Earth's surface is 
Answer:
Total Energy consumed = 146.94 kwh
Total cost = rs 587.76
Explanation:
Given:
3 bulbs each 60 watt [for 3 hours daily]
4 fans each 100 watt [for 8 hours daily
1 electric heater of 2 kWh (2,000 watt) [for half hour daily
]
Rate = rs 4/Kwh
Find:
Total Energy consumed
Total cost
Computation:
Energy used = Power × time
3 bulbs each 60 watt [for 3 hours daily] = 3 x 60 x 3 x 31 = 16,740 watt = 16.74 kw
4 fans each 100 watt [for 8 hours daily = 4 x 100 x 8 x 31 = 99,200 watt = 99.2 kw
1 electric heater of 2 kWh [for half hour daily
] = 1 x 2000 x (1/2) x 31 = 31,000 watt = 31 kw
Total Energy consumed = 16.74 + 99.2 + 31
Total Energy consumed = 146.94 kwh
Total cost = 146.94 x 4
Total cost = rs 587.76