NEET
- Exam
- NEET
- Subject
- Physics
- Chapter
- Alternating Current
NEET · Physics · Alternating Current
Match the following ( Currents r.m.s. values (1) x_ 0 ω t (i) x_ 0...
Match the following
(
)
| Currents | r.m.s. values | ||
| (1) | x_{0}\sin \omega t | (i) | x_{0} |
| (2) | x_{0}\sin \omega t \cos \omega t | (ii) | \tfrac{x_{0}}{\sqrt{2}} |
| (3) | x_{0}\sin \omega t + x_{0}\cos \omega t | (iii) | \tfrac{x_{0}}{2\sqrt{2}} |
Options
- A1 (i),2 (ii),3 (iii)
- B1 (ii), 2 (iii),3 (i)
- C1 (i),2 (iii),3 (ii)
- DNone of these
Correct answer
B. 1 (ii), 2 (iii),3 (i)
Step-by-step solution
1. (x_0 \sin (t)) :
This is a pure sinusoidal function.
The r.m.s. value of a sinusoidal function (A \sin (t)) is (A / ). So, the r.m.s. value of (x_0 \sin (t)) is (x_0 / ).
2. (x_0 \sin (t) \cos (t)) :
Using the trigonometric identity (\sin (2 t)=2 \sin (t) \cos (t)), this can be rewritten as (2 t)), which is again a sinusoidal function. The r.m.s. value will be ().
3. (x_0 \sin (t)+x_0 \cos (t)) : This is a sum of two sinusoidal functions. The r.m.s. value of such a sum can befound by using 2 r.m.s. (=).
Now, match the r.m.s. values:
1. (x_0 \sin (t) → x_0 / ) (ii)
2. (x_0 \sin (t) \cos (t) → x_0 / 2 ) (iii)
3. (x_0 \sin (t)+x_0 \cos (t) → x_0 →) (i)
The correct matching is:
(c) 1 . (ii), 2. (iii), 3. (i)