JEE MAIN - Physics (2019 - 12th January Evening Slot - No. 26)

In the above circuit, C = $${{\sqrt 3 } \over 2}$$$$\mu $$F, R2 = 20 $$\Omega $$, L = $${{\sqrt 3 } \over {10}}$$ H and R1 = 10 $$\Omega $$. Current in L-R1 path is I1 and in C-R2 path it is I2 . The voltage of A.C. source is given by, V = 200 $${\sqrt 2 }$$ sin (100 t) volts . The phase difference between I1 and I2 is :

JEE Main 2019 (Online) 12th January Evening Slot Physics - Alternating Current Question 140 English
150o
90o
30o
0o

Explanation

Phase difference between I2 and V, i.e. C $$-$$ R2 circuit is given by

$$\tan \phi = {{{X_C}} \over {{R_2}}} \Rightarrow \tan \phi = {1 \over {C\omega {R_2}}}$$

Substituting the given values, we get

$$\tan \phi = {1 \over {{{\sqrt 3 } \over 2} \times {{10}^{ - 6}} \times 100 \times 20}} = {{{{10}^3}} \over {\sqrt 3 }}$$

$$\therefore$$ $$\phi$$1 is nearly 90$$^\circ$$.

Phase difference between I1 and V, i.e. in L $$-$$ R1 circuit is given by

$$\tan {\phi _2} = - {{{X_L}} \over {{R_1}}} = - {{L\omega } \over R}$$

Substituting the given values, we get

$$\tan {\phi _2} = - {{{{\sqrt 3 } \over {10}} \times 100} \over {10}} = - \sqrt 3 $$

As, $$\tan {\phi _2} = - \sqrt 3 $$

$$\therefore$$ $${\phi _2} = 120^\circ $$

Now, phase difference between I1 and I2 is

$$\Delta \phi = {\phi _2} - {\phi _1} = 120^\circ - 90^\circ = 30^\circ $$

Comments (0)

Advertisement