Skip to main content

GATE 2020

GATE 2020

1.)Skin depths in homogeneous media of resistivity ρ1 and ρ2 are 100 m and 200 m respectively at 1000Hz frequency. The ratio of ρ1/ρ2 will be......
Ans. Since skin depths are given as 100m and 200 m respectively 
         so using the formula,
                         skin depth (d) =503 √(ρ/f), where ρ-resistivity 
                                                                                         f-frequency
       d1=503√(ρ1/1000)
       d2=503√(ρ2/1000)
          
        now, d1/d2=(√(ρ1/1000)/√(ρ2/1000))
                             =√(ρ1/ρ2)
        ⇒ 100/200 =√(ρ1/ρ2)
                   ρ1/ρ2=1/4
                  ρ1/ρ2 =0.25

Comments

Post a Comment

Popular posts from this blog

GATE Aptitude

Aptitude 2)If  pq = 28 where p and q (p > q) are whole numbers then which of the following can be (p 2  – q 2 )?  a)32  b)83  c)783  d)63 Ans.    p and q can be written in the pairs of (28,1) or (7,4) or (14,2) We have 14 2  – 2 2  = 196 – 4 = 192        Also, 7 2  – 4 2  = 49 – 16 = 33        Also, 28 2  – 1 2  = 784 – 1 = 783        Hence,   p 2  – q 2  = 783
Post a Comment
Read more

GATE Aptitude

Aptitude     1) A person has to make 146 pieces of a long bar. He takes 4 seconds to cut a piece. What is the total time taken by him in seconds to make 146 pieces?  a)584  b)580  c)730  d)725 Ans .  To make 146 pieces there are 145 cuts required         Each cut takes 4 seconds.        Hence the person will require 145 × 4 = 580 seconds.
Post a Comment
Read more