Maths-
General
Easy

Question

If the D. C’s of a line are open parentheses fraction numerator text 1 end text over denominator text c end text end fraction comma fraction numerator text 1 end text over denominator text c end text end fraction comma fraction numerator text 1 end text over denominator text c end text end fraction close parentheses then c is equal to

  1. plus-or-minus 1    
  2. plus-or-minus 2    
  3. plus-or-minus square root of 3    
  4. plus-or-minus square root of 2    

hintHint:

We are given the direction cosines of a line. Direction cosines are values of cosines a line makes with all three axis. The direction cosine contains a variable. We have to find the value of the variable. We will use the properties of direction cosines to find the answer.

The correct answer is: plus-or-minus square root of 3


    The given direction cosines are as follows 1 over c comma 1 over c comma 1 over c
    We will use the properties of direction cosines to find the answer.
    The direction cosines are generally denoted by l, m and n.
    The sum of the square of the direction cosines is 1.
    l+ m2 + n2 = 1
    We will substitute the values.
    open parentheses 1 over c close parentheses squared space plus space open parentheses 1 over c close parentheses squared space plus open parentheses 1 over c close parentheses squared equals space 1
1 over c squared plus space 1 over c squared space plus space 1 over c squared equals 1
T h e space d e n o m i n a t o r space i s space s a m e
W e space c a n space a d d space t h e space n u m e r a t o r s
fraction numerator 1 space plus space 1 space plus space 1 over denominator c squared end fraction equals 1
space space space space space space space space space space space space 3 over c squared equals 1
M u l t i p l y i n g space b o t h space t h e space s i d e s space b y space c squared
space space space space space space space space space space space space space space space 3 space equals space c squared
R e a r r a n i n g space t h e space e q u a t i o n
space space space space space space space space space space space space space space c squared space equals space 3
T a k i n g space t h e space s q u a r e space r o o t
space space space space space space space space space space space space space space c space equals space plus-or-minus square root of 3
    This is the value of c.

    For such questions, we should know the properties of direction cosines.

    Related Questions to study

    General
    Maths-

    The value of f(0) , so that the function f left parenthesis x right parenthesis equals fraction numerator square root of a squared minus a x plus x squared end root minus square root of a squared plus a x plus x squared end root over denominator square root of a plus x end root minus square root of a minus x end root end fraction becomes continuous for all x is given by

    The value of f(0) , so that the function f left parenthesis x right parenthesis equals fraction numerator square root of a squared minus a x plus x squared end root minus square root of a squared plus a x plus x squared end root over denominator square root of a plus x end root minus square root of a minus x end root end fraction becomes continuous for all x is given by

    Maths-General
    General
    Maths-

    Let f, g: R not stretchy rightwards arrow R be two functions defined by f open parentheses x close parentheses equals open curly brackets table row cell x s i n open parentheses fraction numerator 1 over denominator x end fraction close parentheses comma blank end cell row cell 0 blank comma end cell end table table row cell x blank not equal to 0 end cell row cell x equals 0 end cell end table close blankand g(x) = x f(x)
    Statement 1: f is a continuous function at x = 0
    Statement 2: g is a differentiable function at x = 0

    Let f, g: R not stretchy rightwards arrow R be two functions defined by f open parentheses x close parentheses equals open curly brackets table row cell x s i n open parentheses fraction numerator 1 over denominator x end fraction close parentheses comma blank end cell row cell 0 blank comma end cell end table table row cell x blank not equal to 0 end cell row cell x equals 0 end cell end table close blankand g(x) = x f(x)
    Statement 1: f is a continuous function at x = 0
    Statement 2: g is a differentiable function at x = 0

    Maths-General
    General
    Maths-

    lf f left parenthesis theta right parenthesis equals open vertical bar table row 1 cell c o s theta end cell 1 row cell negative s i n theta end cell 1 cell negative c o s theta end cell row cell negative 1 end cell cell s i n theta end cell 1 end table close vertical bar negative 12 x2 and A and 8 are respecively the maximum and the minimum values of left parenthesis theta right parenthesis , then (A, B) is equal to

    lf f left parenthesis theta right parenthesis equals open vertical bar table row 1 cell c o s theta end cell 1 row cell negative s i n theta end cell 1 cell negative c o s theta end cell row cell negative 1 end cell cell s i n theta end cell 1 end table close vertical bar negative 12 x2 and A and 8 are respecively the maximum and the minimum values of left parenthesis theta right parenthesis , then (A, B) is equal to

    Maths-General
    parallel
    General
    Physics-

    Binding energy pernucleonversus mass number curve for nuclei is shown in the figure. W,X,Y and Z are fournuclei indicate don the curve.Theprocessthatwouldrelease

    Binding energy pernucleonversus mass number curve for nuclei is shown in the figure. W,X,Y and Z are fournuclei indicate don the curve.Theprocessthatwouldrelease

    Physics-General
    General
    Physics-

    Which of the plots shown in the figure represents speed(vn) of the electron in a hydrogen atom as a function of theprincipalquantumnumber(n)?

    Which of the plots shown in the figure represents speed(vn) of the electron in a hydrogen atom as a function of theprincipalquantumnumber(n)?

    Physics-General
    General
    Maths-

    lf the Rolle’s theorem holds for the function f left parenthesis x right parenthesis equals 2 x cubed plus a x squared plus b x in the interval [−1, 1] for the point c equals fraction numerator 1 over denominator 2 end fraction , then the value of 2a+b is

    lf the Rolle’s theorem holds for the function f left parenthesis x right parenthesis equals 2 x cubed plus a x squared plus b x in the interval [−1, 1] for the point c equals fraction numerator 1 over denominator 2 end fraction , then the value of 2a+b is

    Maths-General
    parallel
    General
    Physics-

    Ifu subscript 1 end subscriptis the frequency of the series limit of Lymanseries, u subscript 2 end subscriptis the frequency of the firstline of Lymanseries and
    u3 is the frequency of the series limit of the Balmer seriesthen

    Ifu subscript 1 end subscriptis the frequency of the series limit of Lymanseries, u subscript 2 end subscriptis the frequency of the firstline of Lymanseries and
    u3 is the frequency of the series limit of the Balmer seriesthen

    Physics-General
    General
    Physics-

    The diagram shows the energy levels for an electron in acertainatom. Which transitionshown represents theemissionofaphotonwiththemostenergy?

    The diagram shows the energy levels for an electron in acertainatom. Which transitionshown represents theemissionofaphotonwiththemostenergy?

    Physics-General
    General
    Physics-

    Thestopping potentialopen parentheses V subscript 0 end subscript close parentheses, versus frequency(v) plotofasubstance is
    shown in figure, the threshold wavelengthis

    Thestopping potentialopen parentheses V subscript 0 end subscript close parentheses, versus frequency(v) plotofasubstance is
    shown in figure, the threshold wavelengthis

    Physics-General
    parallel
    General
    Physics-

    Thefigureshowsaplotofphotocurrentversusanodepotentialforaphotosensitivesurfaceforthreedifferent radiations.Whichoneofthefollowingisacorrectstatement?

    Thefigureshowsaplotofphotocurrentversusanodepotentialforaphotosensitivesurfaceforthreedifferent radiations.Whichoneofthefollowingisacorrectstatement?

    Physics-General
    General
    Physics-

    Lightofwavelength500nmisincidentonametalwithwork function2.28 eV. The de Broglie wavelengthof the emittedelectronis:

    Lightofwavelength500nmisincidentonametalwithwork function2.28 eV. The de Broglie wavelengthof the emittedelectronis:

    Physics-General
    General
    Physics-

    In an experiment on photoelectric effect, a student plotsstoppingpotentialVO against reciprocalof the wavelengthlambdaoftheincidentlightfortwodifferentmetalsAandB.Theseareshown inthefigure.

    Looking atthegraphs,youcanmostappropriatelysaythat

    In an experiment on photoelectric effect, a student plotsstoppingpotentialVO against reciprocalof the wavelengthlambdaoftheincidentlightfortwodifferentmetalsAandB.Theseareshown inthefigure.

    Looking atthegraphs,youcanmostappropriatelysaythat

    Physics-General
    parallel
    General
    Physics-

    Twoinsulatingplatesarebothuniformlychargedinsuchawaythatthepotentialdifferencebetweenthemis V subscript 2 end subscript-V subscript 1 end subscript=20V.(i.e.,plate2isatahigherpotential).The plates are separatedby d =0.1mand canbe treatedasinfinitelylarge.Anelectronisreleasedfromrestontheinner surfaceofplate1.Whatisitsspeedwhenithitsplate2?

    Twoinsulatingplatesarebothuniformlychargedinsuchawaythatthepotentialdifferencebetweenthemis V subscript 2 end subscript-V subscript 1 end subscript=20V.(i.e.,plate2isatahigherpotential).The plates are separatedby d =0.1mand canbe treatedasinfinitelylarge.Anelectronisreleasedfromrestontheinner surfaceofplate1.Whatisitsspeedwhenithitsplate2?

    Physics-General
    General
    Physics-

    Photoelectric effect experiments are performed using three different metal plates p comma q and r having work functions ϕ subscript p end subscript equals 2.0 e V comma ϕ subscript q end subscript equals 2.5 e V and ϕ subscript r end subscript equals 3.0 e V, respectively. A light beam containing wavelengths of 550 text end text n m comma 450 text end text n m and 350 text end text n m with equal intensities illuminates each of the plates. The correct I minus V graph for the experiment is:
    (Take hc equals 1240 e V n m )

    Photoelectric effect experiments are performed using three different metal plates p comma q and r having work functions ϕ subscript p end subscript equals 2.0 e V comma ϕ subscript q end subscript equals 2.5 e V and ϕ subscript r end subscript equals 3.0 e V, respectively. A light beam containing wavelengths of 550 text end text n m comma 450 text end text n m and 350 text end text n m with equal intensities illuminates each of the plates. The correct I minus V graph for the experiment is:
    (Take hc equals 1240 e V n m )

    Physics-General
    General
    Maths-

    Let f be differentiable for all x. if f(1) = -2 and f to the power of ´ end exponent open parentheses x close parentheses greater or equal than 2 for x element of [1,6], then

    Let f be differentiable for all x. if f(1) = -2 and f to the power of ´ end exponent open parentheses x close parentheses greater or equal than 2 for x element of [1,6], then

    Maths-General
    parallel

    card img

    With Turito Academy.

    card img

    With Turito Foundation.

    card img

    Get an Expert Advice From Turito.

    Turito Academy

    card img

    With Turito Academy.

    Test Prep

    card img

    With Turito Foundation.