Physics · Magnetism and Electromagnetic Induction
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A coil of 600 turns is threaded by a flux of 8x10-5 webers if this flux is reduced to 3x10-5 webers in 0.015 seconds. The average induced e.m.f. is:
- A
-2.0 volts
- B
-3.0 volts
- C
+2.0 volts
- D
+2.5 volts
- E
+3.0 volts
Emf = - N (dФ/dt)
where number of turns are denoted by N, dФ is the change in flux and dt is the time interval.
Change in flux = Final Flux - Initial Flux
Change in flux = (3 × 10⁻⁵) - (8 × 10⁻⁵) Wb
Change in flux = - (5 × 10⁻⁵) Wb
time interval = 0.015 sec
time interval = 15 × 10⁻³ sec
Number of turns in coil = 600
Putting all the values in formula.
Emf = - 600 × (-(5 × 10⁻⁵)/15 × 10⁻³) Volts
Emf = 600 × (5 × 10⁻²/15 ) Volts
Emf = 600 × (10⁻²/3 ) Volts
Emf = 200 × 10⁻² Volts
Emf = 2 Volts
As per explanation, this is incorrect.Emf = - N (dФ/dt)
where number of turns are denoted by N, dФ is the change in flux and dt is the time interval.
Change in flux = Final Flux - Initial Flux
Change in flux = (3 × 10⁻⁵) - (8 × 10⁻⁵) Wb
Change in flux = - (5 × 10⁻⁵) Wb
time interval = 0.015 sec
time interval = 15 × 10⁻³ sec
Number of turns in coil = 600
Putting all the values in formula.
Emf = - 600 × (-(5 × 10⁻⁵)/15 × 10⁻³) Volts
Emf = 600 × (5 × 10⁻²/15 ) Volts
Emf = 600 × (10⁻²/3 ) Volts
Emf = 200 × 10⁻² Volts
Emf = 2 Volts
As per explanation, this is incorrect.Emf = - N (dФ/dt)
where number of turns are denoted by N, dФ is the change in flux and dt is the time interval.
Change in flux = Final Flux - Initial Flux
Change in flux = (3 × 10⁻⁵) - (8 × 10⁻⁵) Wb
Change in flux = - (5 × 10⁻⁵) Wb
time interval = 0.015 sec
time interval = 15 × 10⁻³ sec
Number of turns in coil = 600
Putting all the values in formula.
Emf = - 600 × (-(5 × 10⁻⁵)/15 × 10⁻³) Volts
Emf = 600 × (5 × 10⁻²/15 ) Volts
Emf = 600 × (10⁻²/3 ) Volts
Emf = 200 × 10⁻² Volts
Emf = 2 Volts
N=600
1=810-5Wb
2=310-5Wb
Solution:
=1-2=810-5-310-5=510-5Wb
t=0.015s
Induced Emf==?
As, =-N/t
=(-600510-5)/0.015
=2V
Result:
=2V
Emf = - N (dФ/dt)
where number of turns are denoted by N, dФ is the change in flux and dt is the time interval.
Change in flux = Final Flux - Initial Flux
Change in flux = (3 × 10⁻⁵) - (8 × 10⁻⁵) Wb
Change in flux = - (5 × 10⁻⁵) Wb
time interval = 0.015 sec
time interval = 15 × 10⁻³ sec
Number of turns in coil = 600
Putting all the values in formula.
Emf = - 600 × (-(5 × 10⁻⁵)/15 × 10⁻³) Volts
Emf = 600 × (5 × 10⁻²/15 ) Volts
Emf = 600 × (10⁻²/3 ) Volts
Emf = 200 × 10⁻² Volts
Emf = 2 Volts
As per explanation, this is incorrect.Emf = - N (dФ/dt)
where number of turns are denoted by N, dФ is the change in flux and dt is the time interval.
Change in flux = Final Flux - Initial Flux
Change in flux = (3 × 10⁻⁵) - (8 × 10⁻⁵) Wb
Change in flux = - (5 × 10⁻⁵) Wb
time interval = 0.015 sec
time interval = 15 × 10⁻³ sec
Number of turns in coil = 600
Putting all the values in formula.
Emf = - 600 × (-(5 × 10⁻⁵)/15 × 10⁻³) Volts
Emf = 600 × (5 × 10⁻²/15 ) Volts
Emf = 600 × (10⁻²/3 ) Volts
Emf = 200 × 10⁻² Volts
Emf = 2 Volts
Tagged under Physics · Magnetism and Electromagnetic Induction