Explore topic-wise MCQs in Joint Entrance Exam - Main (JEE Main).

This section includes 8666 Mcqs, each offering curated multiple-choice questions to sharpen your Joint Entrance Exam - Main (JEE Main) knowledge and support exam preparation. Choose a topic below to get started.

6701.

If \[f(x)=\left\{ \begin{align}   & x-1,\,\,\,x0 \\ \end{align} \right.\], then [Roorkee 1988]

A.            \[\underset{x\to 0+}{\mathop{\lim }}\,f(x)=1\]
B.            \[\underset{x\to 0-}{\mathop{\lim }}\,f(x)=1\]
C.            \[f(x)\]is discontinuous at\[x=0\]    
D.            None of these
Answer» D.            None of these
6702.

If \[f(x)=\left\{ \begin{align}   & \frac{1}{x}\sin {{x}^{2}},\,x\ne 0 \\  & \,\,\,\,\,\,\,\,\,\,\,\,\,\,0,\,x=0 \\ \end{align} \right.\], then

A.            \[\underset{x\to 0+}{\mathop{\lim }}\,f(x)\ne 0\]
B.            \[\underset{x\to 0-}{\mathop{\lim }}\,f(x)\ne 0\]
C.  f(x) is continuous at\[x=0\]
D.            None of these
Answer» D.            None of these
6703.

If \[f(x)=\left\{ \begin{align}   & {{2}^{1/x}},\text{for}\,x\ne 0 \\  & \,\,\,\,\,\,\,3,\text{for}\,x=\text{0} \\ \end{align} \right.\], then

A.            \[\underset{x\to 0+}{\mathop{\lim }}\,f(x)=0\]
B.            \[\underset{x\to 0-}{\mathop{\lim }}\,f(x)=\infty \]
C.            \[f(x)\]is continuous at\[x=0\]
D.  None of these
Answer» E.
6704.

If \[f(x)=\left\{ \begin{align}   & {{(1+2x)}^{1/x}},\,\text{for }x\ne 0 \\  & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{{e}^{2}},\,\text{for }x=0\,\,\, \\ \end{align} \right.\], then

A.   \[\underset{x\to 0+}{\mathop{\lim }}\,f(x)=e\]                                   
B.            \[\underset{x\to 0-}{\mathop{\lim }}\,f(x)={{e}^{2}}\]
C.            \[f(x)\]is discontinuous at \[x=0\]   
D.            None of these
Answer» C.            \[f(x)\]is discontinuous at \[x=0\]   
6705.

If \[f(x)=\left\{ \begin{align}   & \frac{x}{{{e}^{1/x}}+1},\,\,\text{when}\,\,x\ne 0 \\  & \,\,\,\,\,\,\,\,\,\,\,\,\,\,0,\,\,\text{when }x=0 \\ \end{align} \right.\], then

A.            \[\underset{x\to 0+}{\mathop{\lim }}\,f(x)=1\]
B.            \[\underset{x\to 0-}{\mathop{\lim }}\,f(x)=1\]
C.            \[f(x)\]is continuous at\[x=0\]
D.            None of these
Answer» D.            None of these
6706.

The value of k so that the function \[f(x)=\left\{ \begin{align}   & k(2x-{{x}^{2}}),\ \ \ \text{when}\,x

A.            1
B.            2
C.            4
D.            None of these
Answer» E.
6707.

If \[f(x)=\left\{ \begin{align}   & {{x}^{2}}\sin \frac{1}{x},\ \ \ \text{when }x\ne 0 \\  & \,\,\,\,\,\,\,\,\,\,\,\,\,\,0,\,\,\,\,\text{when}\,x=0 \\ \end{align} \right.\], then

A.            \[f(0+0)=1\]
B.            \[f(0-0)=1\]
C.            f is continuous at\[x=0\]
D.            None of these
Answer» D.            None of these
6708.

If \[f(x)=\left\{ \begin{matrix}    {{e}^{x}}+ax, & x

A.            \[\underset{x\to 0+}{\mathop{\lim }}\,f(x)\ne 2\]
B.            \[\underset{x\to 0-}{\mathop{\lim }}\,f(x)=0\]
C.            \[f(x)\]is continuous at\[x=0\]
D.            None of these
Answer» D.            None of these
6709.

The points at which the function \[f(x)=\frac{x+1}{{{x}^{2}}+x-12}\] is discontinuous, are

A.            ?3, 4
B.            3, ?4
C.            ?1,?3, 4
D.            ?1, 3, 4
Answer» C.            ?1,?3, 4
6710.

If \[f(x)=\left\{ \begin{align}   & \frac{{{x}^{2}}-4x+3}{{{x}^{2}}-1},\ \text{for}\ x\ne 1 \\  & \ \ \ \ \ \ \ \ \ \ \ \ \ \ 2,\ \text{for }x=1 \\ \end{align} \right.\], then [IIT 1972]

A.            \[\underset{x\to 1+}{\mathop{\lim }}\,f(x)=2\]
B.            \[\underset{x\to 1-}{\mathop{\lim }}\,f(x)=3\]
C.            \[f(x)\]is discontinuous at \[x=1\]
D.            None of these
Answer» D.            None of these
6711.

If\[f(x)=|x-2|\], then [Roorkee 1984]

A.            \[\underset{x\to 2+}{\mathop{\lim }}\,f(x)\ne 0\]                     
B.            \[\underset{x\to 2-}{\mathop{\lim }}\,f(x)\ne 0\]
C.            \[\underset{x\to 2+}{\mathop{\lim }}\,f(x)\ne \underset{x\to 2-}{\mathop{\lim }}\,f(x)\]   
D.            \[f(x)\]is continuous at \[x=2\]
Answer» E.
6712.

8th term of the series \[2\sqrt{2}+\sqrt{2}+0+.....\] will be

A. \[-5\sqrt{2}\]
B. \[5\sqrt{2}\]
C. \[10\sqrt{2}\]
D. \[-10\sqrt{2}\]
Answer» B. \[5\sqrt{2}\]
6713.

The radius of a sphere is measured to be 20 cm with a possible error of 0.02 of a cm. The consequent error in the surface of the sphere is

A.            \[10.5\] sq cm
B.            5.025 sq cm
C.            10.05 sq cm
D.            None of these
Answer» D.            None of these
6714.

In a Boolean Algebra B, for all x, y in B,\[(x\vee y{)}'=\]

A.      \[{x}'\vee {y}'\]
B.      \[{x}'\wedge {y}'\]
C.      1  
D.      None of these
Answer» C.      1  
6715.

In a bag there are three tickets numbered 1, 2, 3. A ticket is drawn at random and put back and this is done four times. The probability that the sum of the numbers is even, is

A.      \[\frac{41}{81}\]  
B.      \[\frac{39}{81}\]
C.      \[\frac{40}{81}\]  
D.      None of these
Answer» B.      \[\frac{39}{81}\]
6716.

In a Boolean Algebra B, for all x in B, \[{0}'\] is equal to

A.      0  
B.      1
C.      \[x.0\]  
D.      None of these
Answer» C.      \[x.0\]  
6717.

A spherical balloon is being inflated at the rate of 35 cc/min. The rate of increase of the surface area of the balloon when its diameter is 14 cm is [Karnataka CET 2005]

A.            7 sq. cm/min
B.            10 sq. cm/min
C.            17.5 sq. cm/min
D.            28 sq. cm/min
Answer» C.            17.5 sq. cm/min
6718.

If the line \[2x+3ay-1=0\] and \[3x+4y+1=0\] are mutually perpendicular, then the value of a will be      [MNR 1975]

A.            \[\frac{1}{2}\]    
B. 2
C.            \[-\frac{1}{2}\]  
D. None of these
Answer» D. None of these
6719.

If \[A\] be a arithmetic mean between two numbers and \[S\] be the sum of \[n\] arithmetic means between the same numbers, then

A. \[S=n\,A\]
B. \[A=n\,S\]
C. \[A=S\]
D. None of these
Answer» B. \[A=n\,S\]
6720.

If x is real, then the maximum and minimum values of expression \[\frac{{{x}^{2}}+14x+9}{{{x}^{2}}+2x+3}\] will be [Dhanbad Engg. 1968]

A. 4, - 5
B. 5,  - 4
C. - 4, 5
D. - 4, - 5
Answer» B. 5,  - 4
6721.

The \[{{n}^{th}}\] term of an A.P. is \[3n-1\].Choose from the following the sum of its first five terms [MP PET 1983]

A. 14
B. 35
C. 80
D. 40
Answer» E.
6722.

The sum of the numbers between 100 and 1000 which is divisible by 9 will be [MP PET 1982]

A. 55350
B. 57228
C. 97015
D. 62140
Answer» B. 57228
6723.

\[2+4+7+11+16+......\]to \[n\]  terms = [Roorkee 1977]

A. \[\frac{1}{6}({{n}^{2}}+3n+8)\]
B. \[\frac{n}{6}({{n}^{2}}+3n+8)\]
C. \[\frac{1}{6}({{n}^{2}}-3n+8)\]
D. \[\frac{n}{6}({{n}^{2}}-3n+8)\]
Answer» C. \[\frac{1}{6}({{n}^{2}}-3n+8)\]
6724.

. If \[{{\log }_{3}}2,\ {{\log }_{3}}({{2}^{x}}-5)\] and \[{{\log }_{3}}\left( {{2}^{x}}-\frac{7}{2} \right)\] are in A.P., then \[x\] is equal to [IIT 1990]

A. \[1,\ \frac{1}{2}\]
B. \[1,\ \frac{1}{3}\]
C. \[1,\ \frac{3}{2}\]
D. None of these
Answer» E.
6725.

\[{{99}^{th}}\] term of the series \[2+7+14+23+34+.....\] is [Pb. CET 2003]

A. 9998
B. 9999
C. 10000
D. 100000
Answer» B. 9999
6726.

Two cards are drawn one by one from a pack of cards.  The probability of getting first card an ace and second a colored one is (before drawing second card first card is not placed again in the pack)      [UPSEAT 1999; 2003]

A.      \[\frac{1}{26}\]    
B.      \[\frac{5}{52}\]
C.      \[\frac{5}{221}\]  
D.      \[\frac{4}{13}\]
Answer» D.      \[\frac{4}{13}\]
6727.

The points \[(at_{1}^{2},2a{{t}_{1}}),(at_{2}^{2},2a{{t}_{2}})\]and \[(a,0)\]will be collinear, if

A.            \[{{t}_{1}}{{t}_{2}}=1\]  
B.            \[{{t}_{1}}{{t}_{2}}=-1\]
C.            \[{{t}_{1}}+{{t}_{2}}=1\]
D.            \[{{t}_{1}}+{{t}_{2}}=-1\]
Answer» C.            \[{{t}_{1}}+{{t}_{2}}=1\]
6728.

If the ordinate \[x=a\] divides the area bounded by the curve \[y=\left( 1+\frac{8}{{{x}^{2}}} \right)\,,\] \[x-\]axis and the ordinates \[x=2,\] \[x=4\] into two equal parts, then \[a=\] [IIT 1983]

A.            8    
B.            \[2\sqrt{2}\]
C.            2    
D.            \[\sqrt{2}\]
Answer» C.            2    
6729.

The vector equation of the plane passing through the origin and the line of intersection of the plane \[\mathbf{r}.\mathbf{a}=\lambda \] and \[\mathbf{r}.\mathbf{b}=\mu \] is

A.            \[\mathbf{r}.(\lambda \mathbf{a}-\mu \mathbf{b})=0\]
B.            \[\mathbf{r}.\,(\lambda \mathbf{b}-\mu \mathbf{a})=0\]
C.            \[\mathbf{r}.(\lambda \mathbf{a}+\mu \mathbf{b})=0\]
D.            \[\mathbf{r}.(\lambda \mathbf{b}+\mu \mathbf{a})=0\]
Answer» C.            \[\mathbf{r}.(\lambda \mathbf{a}+\mu \mathbf{b})=0\]
6730.

If  \[{{z}_{1}}\] and \[{{z}_{2}}\]  are two non-zero complex numbers such that \[|{{z}_{1}}+{{z}_{2}}|=|{{z}_{1}}|+|{{z}_{2}}|,\]then arg \[({{z}_{1}})-\]arg \[({{z}_{2}})\] is equal to     [IIT  1979, 1987; EAMCET 1986; RPET 1997; MP PET 2001; AIEEE 2005]

A. \[-\pi \]
B. \[-\frac{\pi }{2}\]
C. \[\frac{\pi }{2}\]
D. 0
Answer» E.
6731.

Two cards are drawn successively with replacement from a well shuffled deck of 52 cards then the mean of the number of aces is               [J & K 2005]

A.      1/13       
B.      3/13
C.      2/13       
D.      None of these
Answer» D.      None of these
6732.

The ratio of sum of \[m\] and \[n\] terms  of an A.P. is \[{{m}^{2}}:{{n}^{2}}\], then the ratio of \[{{m}^{th}}\]and \[{{n}^{th}}\] term will be [Roorkee 1963; MP PET 1995; Pb. CET 2001]

A. \[\frac{m-1}{n-1}\]
B. \[\frac{n-1}{m-1}\]
C. \[\frac{2m-1}{2n-1}\]
D. \[\frac{2n-1}{2m-1}\]
Answer» D. \[\frac{2n-1}{2m-1}\]
6733.

The conjugate of \[\frac{{{(2+i)}^{2}}}{3+i},\] in the form of a +  ib, is  [Karnataka CET 2001; Pb. CET 2001]

A. \[\frac{13}{2}+i\,\left( \frac{15}{2} \right)\]
B. \[\frac{13}{10}+i\left( \frac{-15}{2} \right)\]
C. \[\frac{13}{10}+i\,\left( \frac{-9}{10} \right)\]
D. \[\frac{13}{10}+i\,\left( \frac{9}{10} \right)\]
Answer» D. \[\frac{13}{10}+i\,\left( \frac{9}{10} \right)\]
6734.

The area bounded by the circle \[{{x}^{2}}+{{y}^{2}}=4,\] line \[x=\sqrt{3}y\] and \[x-\]axis lying in the first quadrant, is [RPET 1997; Kurukshetra CEE 1998]

A.            \[\frac{\pi }{2}\]      
B.            \[\frac{\pi }{4}\]
C.            \[\frac{\pi }{3}\]      
D.            \[\pi \]
Answer» D.            \[\pi \]
6735.

In a Boolean Algebra B, for all x in B, \[x\vee x=\]

A.      0  
B.      1
C.      x  
D.      None of these
Answer» D.      None of these
6736.

Area of the ellipse \[\frac{{{x}^{2}}}{{{a}^{2}}}+\frac{{{y}^{2}}}{{{b}^{2}}}=1\] is      [Karnataka CET 1993]

A.            \[\pi \,ab\]sq. unit  
B.            \[\frac{1}{2}\pi \,ab\]sq. unit
C.            \[\frac{1}{4}\pi \,ab\]sq. unit
D.            None of these
Answer» B.            \[\frac{1}{2}\pi \,ab\]sq. unit
6737.

A particle moves in a straight line so that its velocity at any point is given by \[{{v}^{2}}=a+bx\], where \[a,b\ne 0\]are constants. The acceleration is [MP PET 1989]

A.            Zero
B.            Uniform
C.            Non-uniform
D.            Indeterminate
Answer» C.            Non-uniform
6738.

If \[{{n}^{th}}\]  terms of two A.P.'s are \[3n+8\] and \[7n+15\], then the ratio of their \[{{12}^{th}}\] terms will be  [MP PET 1986]

A. 44443
B. 42552
C. 44380
D. 42217
Answer» B. 42552
6739.

 A stone moving vertically upwards has its equation of motion \[s=490t-4.9{{t}^{2}}\].  The maximum height reached by the stone is

A.            12250
B.            1225
C.            36750
D.            None of these
Answer» B.            1225
6740.

\[{{(r+1)}^{th}}\] term in the expansion of \[{{(1-x)}^{-4}}\]will be

A. \[\frac{{{x}^{r}}}{r!}\]
B. \[\frac{(r+1)(r+2)(r+3)}{6}{{x}^{r}}\]
C. \[\frac{(r+2)(r+3)}{2}{{x}^{r}}\]
D. None of these
Answer» C. \[\frac{(r+2)(r+3)}{2}{{x}^{r}}\]
6741.

The angle between the lines \[xy=0\]is equal to [Pb. CET 2003]

A.            \[{{45}^{o}}\]
B.            \[60{}^\circ \]
C.            \[{{90}^{o}}\]
D.            \[{{180}^{o}}\]
Answer» D.            \[{{180}^{o}}\]
6742.

One dice is thrown three times and the sum of the thrown numbers is 15. The probability for which number 4 appears in first throw    [MP PET 2004]

A.      \[\frac{1}{18}\]    
B.      \[\frac{1}{36}\]
C.      \[\frac{1}{9}\]       
D.      \[\frac{1}{3}\]
Answer» B.      \[\frac{1}{36}\]
6743.

The centre of the conic represented by the equation \[2{{x}^{2}}-72xy+23{{y}^{2}}-4x-28y-48=0\] is

A.            \[\left( \frac{11}{15},\ \frac{2}{25} \right)\]    
B.            \[\left( \frac{2}{25},\ \frac{11}{25} \right)\]
C.            \[\left( \frac{11}{15},\ -\frac{2}{25} \right)\]   
D.            \[\left( -\frac{11}{25},\ -\frac{2}{25} \right)\]
Answer» B.            \[\left( \frac{2}{25},\ \frac{11}{25} \right)\]
6744.

A line through (0,0) cuts the circle \[{{x}^{2}}+{{y}^{2}}-2ax=0\] at A and B, then locus of the centre of the circle drawn on AB as a diameter is [RPET 2002]

A.            \[{{x}^{2}}+{{y}^{2}}-2ay=0\]       
B.            \[{{x}^{2}}+{{y}^{2}}+ay=0\]
C.            \[{{x}^{2}}+{{y}^{2}}+ax=0\]       
D.            \[{{x}^{2}}+{{y}^{2}}-ax=0\]
Answer» E.
6745.

If the equation \[{{x}^{2}}+px+q=0\] and \[{{x}^{2}}+qx+p=0\], have a common root, then \[p+q+1=\] [Orissa JEE 2002]

A. 0
B. 1
C. 2
D. -1
Answer» B. 1
6746.

For two events A and B, if \[P(A)=P\left( \frac{A}{B} \right)=\frac{1}{4}\] and \[P\,\left( \frac{B}{A} \right)=\frac{1}{2},\] then

A.      A and B are independent    
B.      \[P\,\left( \frac{{{A}'}}{B} \right)=\frac{3}{4}\]
C.      \[P\,\left( \frac{{{B}'}}{{{A}'}} \right)=\frac{1}{2}\]      
D.      All of the above
Answer» E.
6747.

Middle point of the chord of the circle \[{{x}^{2}}+{{y}^{2}}=25\] intercepted on the line \[x-2y=2\]is

A.            \[\left( \frac{3}{5},\frac{4}{5} \right)\]    
B.            \[(-2,-2)\]
C.            \[\left( \frac{2}{5},-\frac{4}{5} \right)\]   
D.            \[\left( \frac{8}{3},\frac{1}{3} \right)\]
Answer» D.            \[\left( \frac{8}{3},\frac{1}{3} \right)\]
6748.

The sum of \[n\] arithmetic means between \[a\] and \[b\], is [RPET 1986]

A. \[\frac{n(a+b)}{2}\]
B. \[n(a+b)\]
C. \[\frac{(n+1)(a+b)}{2}\]
D. \[(n+1)(a+b)\]
Answer» B. \[n(a+b)\]
6749.

If a curve \[y=a\sqrt{x}+bx\] passes through the point (1, 2) and the area bounded by the curve, line \[x=4\] and  x-axis is     8 sq. unit, then [MP PET 2002]

A.            \[a=3,\,b=-1\]          
B.            \[a=3,\,b=1\]
C.            \[a=-3,\,b=1\]          
D.            \[a=-3,\,b=-1\]
Answer» B.            \[a=3,\,b=1\]
6750.

A real value of x will satisfy the equation \[\left( \frac{3-4ix}{3+4ix} \right)=\] \[\alpha -i\beta \,(\alpha ,\beta \,\text{real),}\] if [Orissa JEE 2003]

A. \[{{\alpha }^{2}}-{{\beta }^{2}}=-1\]
B. \[{{\alpha }^{2}}-{{\beta }^{2}}=1\]
C. \[{{\alpha }^{2}}+{{\beta }^{2}}=1\]
D. \[{{\alpha }^{2}}-{{\beta }^{2}}=2\]
Answer» D. \[{{\alpha }^{2}}-{{\beta }^{2}}=2\]