If z is a complex number of unit modulus and argument θ, then

Subject

Mathematics

Class

JEE Class 12

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

11.

The equation of the circle passing through the foci of the ellipse straight x squared over 16 space plus straight y squared over 9 space equals 1 and having centre at (0,3) is 

  • x2+y2-6y-7 =0

  • x2+y2-6y+7 =0

  • x2+y2-6y-5 =0

  • x2+y2-6y-5 =0

225 Views

12.

A multiple choice examination has 5 questions. Each question has three alternative answers of which exactly one is correct. The probability that a student will get 4 or more correct answers just by guessing is

  • 17/35

  • 13/35

  • 11/35

  • 11/35

168 Views

13.

The x-coordinate of the incentre of the triangle that has the coordinates of mid points of its sides as (0, 1) (1, 1) and (1, 0) is

  • 2 plus square root of 2
  • 2 minus square root of 2
  • 1 plus square root of 2
  • 1 plus square root of 2
160 Views

14.

The term independent of  x in open parentheses fraction numerator straight x plus 1 over denominator straight x to the power of 2 divided by 3 end exponent minus straight x to the power of 1 divided by 3 end exponent space plus 1 end fraction minus fraction numerator straight x minus 1 over denominator straight x minus straight x to the power of 1 divided by 2 end exponent end fraction close parentheses to the power of 10 is 

  • 4

  • 120

  • 18

  • 18

171 Views

Advertisement
15.

Let Tn be the number of all possible triangles formed by joining vertices of an n-sided regular polygon. If Tn+1 − Tn = 10, then the value of n is

  • 7

  • 5

  • 10

  • 10

266 Views

Advertisement

16.

If z is a complex number of unit modulus and argument θ, then arg open parentheses fraction numerator 1 plus straight z over denominator 1 plus straight z with bar on top end fraction close parentheses is equal to

  • π/2-θ

  • θ

  • θ


C.

θ

Given, |z| =1,arg z = θ
z =eiθ
top enclose straight z space equals space 1 over straight z
therefore space arg space open parentheses fraction numerator 1 plus straight z over denominator 1 plus begin display style 1 over straight z end style end fraction close parentheses space equals space arg space left parenthesis straight z right parenthesis space equals straight theta

223 Views

Advertisement
17.

ABCD is a trapezium such that AB and CD are parallel and BC⊥CD. If ∠ADB = θ, BC = p and CD = q,then AB is equal to

  • fraction numerator left parenthesis straight p squared plus straight q squared right parenthesis space sin space straight theta over denominator straight p space cos space straight theta space plus space straight q space sin space straight theta end fraction
  • fraction numerator straight p squared space plus straight q squared space cos space straight theta over denominator straight p squared space cos space straight theta space plus space straight q space sin space straight theta end fraction
  • fraction numerator straight p squared plus straight q squared space cos space straight theta over denominator straight p squared space cos space straight theta space plus straight q space sin space straight theta end fraction
  • fraction numerator straight p squared plus straight q squared space cos space straight theta over denominator straight p squared space cos space straight theta space plus straight q space sin space straight theta end fraction
198 Views

18.

Given A circle, 2x2 + 2y2= 5 and parabola, straight y squared space equals space 4 square root of 5 space straight x 
Statement I An equation of a common tangent to these curves is straight y space equals straight x plus square root of 5
Statement II If the line straight y space equals space mx space plus fraction numerator space square root of 5 over denominator straight m end fraction space left parenthesis straight m space not equal to 0 right parenthesis is the common tangent, then m satisfies m4-3m2+2 =0

  • Statement I is true,  Statement II is true; Statement II is a correct explanation for statement I

  • Statement I is true, Statement II is true; Statement II is not a correct explanation for statement I

  • Statement I is true, Statement II is false

  • Statement I is true, Statement II is false

238 Views

Advertisement
19.

The expression fraction numerator tan space straight A over denominator 1 minus cot space straight A end fraction plus space fraction numerator cot space straight A over denominator 1 minus space tan space straight A end fraction can be written as

  • sin A cos A+1

  • sec A cosec A+1

  • tan A + cot A

  • tan A + cot A

148 Views

20.

All the students of a class performed poorly in Mathematics. The teacher decided to give grace marks of 10 to each of the students. Which of the following statistical measures will not change even after the grace marks were given?

  • Mean

  • Median

  • Mode

  • Mode

204 Views

Advertisement