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.

4601.

The G.M. of the numbers \[3,\,{{3}^{2}},\,{{3}^{3}},....,\,{{3}^{n}}\] is  [DCE 2002]

A. \[{{3}^{\frac{2}{n}}}\]
B. \[{{3}^{\frac{n+1}{2}}}\]
C. \[{{3}^{\frac{n}{2}}}\]
D. \[{{3}^{\frac{n-1}{2}}}\]
Answer» C. \[{{3}^{\frac{n}{2}}}\]
4602.

The number which should be added to the numbers 2, 14, 62 so that the resulting numbers may be in G.P., is

A. 1
B. 2
C. 3
D. 4
Answer» C. 3
4603.

 If five G.M.?s are inserted between 486 and 2/3 then fourth G.M. will be   [RPET 1999]

A. 4
B. 6
C. 12
D. -6
Answer» C. 12
4604.

If three geometric means be inserted between 2 and 32, then the third geometric mean will be

A. 8
B. 4
C. 16
D. 12
Answer» D. 12
4605.

If \[G\] be the geometric mean of \[x\] and \[y\], then \[\frac{1}{{{G}^{2}}-{{x}^{2}}}+\frac{1}{{{G}^{2}}-{{y}^{2}}}=\]

A. \[{{G}^{2}}\]
B. \[\frac{1}{{{G}^{2}}}\]
C. \[\frac{2}{{{G}^{2}}}\]
D. \[3{{G}^{2}}\]
Answer» C. \[\frac{2}{{{G}^{2}}}\]
4606.

If the geometric mean between \[a\] and \[b\] is \[\frac{{{a}^{n+1}}+{{b}^{n+1}}}{{{a}^{n}}+{{b}^{n}}}\],  then the value of n is

A. 1
B. -0.5
C. 44228
D. 2
Answer» C. 44228
4607.

If \[n\] geometric means be inserted between \[a\] and \[b\]then the \[{{n}^{th}}\] geometric mean will be

A. \[a\,{{\left( \frac{b}{a} \right)}^{\frac{n}{n-1}}}\]
B.   \[a\,{{\left( \frac{b}{a} \right)}^{\frac{n-1}{n}}}\]
C. \[a\,{{\left( \frac{b}{a} \right)}^{\frac{n}{n+1}}}\]
D. \[a\,{{\left( \frac{b}{a} \right)}^{\frac{1}{n}}}\]
Answer» D. \[a\,{{\left( \frac{b}{a} \right)}^{\frac{1}{n}}}\]
4608.

The first term of a G.P. is 7, the last term is 448 and sum of all terms is 889, then the common ratio is  [MP PET 2003]

A. 5
B. 4
C. 3
D. 2
Answer» E.
4609.

Three numbers are in G.P. such that their sum is 38 and their product is 1728. The greatest number among them is [UPSEAT 2004]

A. 18
B. 16
C. 14
D. None of these
Answer» B. 16
4610.

The sum of the series \[3+33+333+...+n\] terms is [RPET 2000]

A. \[\frac{1}{27}({{10}^{n+1}}+9n-28)\]
B. \[\frac{1}{27}({{10}^{n+1}}-9n-10)\]
C. \[\frac{1}{27}({{10}^{n+1}}+10n-9)\]
D. None of these
Answer» C. \[\frac{1}{27}({{10}^{n+1}}+10n-9)\]
4611.

The product of \[n\] positive numbers is unity. Their sum is  [MP PET 2000]

A. A positive integer
B. Equal to \[n+\frac{1}{n}\]
C. Divisible by \[n\]
D. Never less than
Answer» E.
4612.

If the first  term of a G.P. be 5 and common ratio be \[-5\], then which term is 3125

A. \[{{6}^{th}}\]
B. \[{{5}^{th}}\]
C. \[{{7}^{th}}\]
D. \[{{8}^{th}}\]
Answer» C. \[{{7}^{th}}\]
4613.

If in a geometric progression \[\left\{ {{a}_{n}} \right\},\ {{a}_{1}}=3,\ {{a}_{n}}=96\] and \[{{S}_{n}}=189\] then the value of \[n\] is

A. 5
B. 6
C. 7
D. 8
Answer» C. 7
4614.

The solution of the equation \[1+a+{{a}^{2}}+{{a}^{3}}+.......+{{a}^{x}}\] \[=(1+a)(1+{{a}^{2}})(1+{{a}^{4}})\] is given by \[x\] is equal to

A. 3
B. 5
C. 7
D. None of these
Answer» D. None of these
4615.

For a sequence \[,\ {{a}_{1}}=2\] and \[\frac{{{a}_{n+1}}}{{{a}_{n}}}=\frac{1}{3}\]. Then \[\sum\limits_{r=1}^{20}{{{a}_{r}}}\] is

A. \[\frac{20}{2}[4+19\times 3]\]
B. \[3\left( 1-\frac{1}{{{3}^{20}}} \right)\]
C. \[2(1-{{3}^{20}})\]
D. None of these
Answer» C. \[2(1-{{3}^{20}})\]
4616.

The number \[111..............1\] (91 times) is a

A. Even number
B. Prime number
C. Not prime
D. None of these
Answer» D. None of these
4617.

The sum of \[n\] terms of the following series \[1+(1+x)+(1+x+{{x}^{2}})+..........\]will be [IIT 1962]

A. \[\frac{1-{{x}^{n}}}{1-x}\]
B. \[\frac{x(1-{{x}^{n}})}{1-x}\]
C. \[\frac{n(1-x)-x(1-{{x}^{n}})}{{{(1-x)}^{2}}}\]
D. None of these
Answer» D. None of these
4618.

If the sum of first  6 term is 9 times to the sum of first 3 terms of the same G.P., then the common ratio of the series will be [RPET 1985]

A. \[-2\]
B. 2
C. 1
D. 44228
Answer» C. 1
4619.

If the sum of \[n\] terms of a G.P. is 255 and \[{{n}^{th}}\]terms is 128 and common ratio is 2, then first term will be  [RPET 1990]

A. 1
B. 3
C. 7
D. None of these
Answer» B. 3
4620.

If every term of a G.P. with positive terms is the sum of its two previous terms, then the common ratio of the series is [RPET 1986]

A. 1
B. \[\frac{2}{\sqrt{5}}\]
C. \[\frac{\sqrt{5}-1}{2}\]
D. \[\frac{\sqrt{5}+1}{2}\]
Answer» E.
4621.

If the \[{{4}^{th}},\ {{7}^{th}}\] and \[{{10}^{th}}\] terms of  a G.P. be \[a,\ b,\ c\] respectively, then the relation between \[a,\ b,\ c\] is [MNR 1995; Karnataka CET 1999]

A. \[b=\frac{a+c}{2}\]
B. \[{{a}^{2}}=bc\]
C. \[{{b}^{2}}=ac\]
D. \[{{c}^{2}}=ab\]
Answer» D. \[{{c}^{2}}=ab\]
4622.

The sum of the series \[6+66+666+..........\]upto \[n\] terms is [IIT 1974]

A. \[({{10}^{n-1}}-9n+10)/81\]
B. \[2({{10}^{n+1}}-9n-10)/27\]
C. \[2({{10}^{n}}-9n-10)/27\]
D. None of these
Answer» C. \[2({{10}^{n}}-9n-10)/27\]
4623.

The value of \[0.\overset{\,\,\,\,\,\,\bullet \,\,\,\,\bullet \,\,\,}{\mathop{234}}\,\] is   [MNR 1986; UPSEAT 2000]

A. \[\frac{232}{990}\]
B. \[\frac{232}{9990}\]
C. \[\frac{232}{990}\]
D. \[\frac{232}{9909}\]
Answer» B. \[\frac{232}{9990}\]
4624.

The sum of 100 terms of the series \[.9+.09+.009.........\]will be

A. \[1-{{\left( \frac{1}{10} \right)}^{100}}\]
B. \[1+{{\left( \frac{1}{10} \right)}^{100}}\]
C. \[\]\[1-{{\left( \frac{1}{10} \right)}^{106}}\]
D. \[1+{{\left( \frac{1}{10} \right)}^{100}}\]
Answer» B. \[1+{{\left( \frac{1}{10} \right)}^{100}}\]
4625.

The sum of the first five terms of the series \[3+4\frac{1}{2}+6\frac{3}{4}+......\] will be

A. \[39\frac{9}{16}\]
B. \[18\frac{3}{16}\]
C. \[39\frac{7}{16}\]
D. \[13\frac{9}{16}\]
Answer» B. \[18\frac{3}{16}\]
4626.

If the sum of an infinite G.P. be 9 and the sum of first two terms be 5, then the common ratio is

A. 44256
B. 44230
C. 44289
D. 44257
Answer» E.
4627.

Fifth term of a G.P. is 2, then the product of its 9 terms is    [Pb. CET 1990, 94; AIEEE 2002]

A. 256
B. 512
C. 1024
D. None of these
Answer» C. 1024
4628.

The third term of a G.P. is the square of first term. If the second term is 8, then the \[{{6}^{th}}\] term is [MP PET 1997]

A. 120
B. 124
C. 128
D. 132
Answer» D. 132
4629.

If the nth term of geometric progression \[5,-\frac{5}{2},\frac{5}{4},-\frac{5}{8},...\] is \[\frac{5}{1024}\], then the value of n is [Kerala (Engg.) 2002]

A. 11
B. 10
C. 9
D. 4
Answer» B. 10
4630.

\[{{7}^{th}}\] term of the sequence \[\sqrt{2},\ \sqrt{10},\ 5\sqrt{2},\ .......\]is

A. \[125\sqrt{10}\]
B. \[25\sqrt{2}\]
C. 125
D. \[125\sqrt{2}\]
Answer» E.
4631.

If the \[{{10}^{th}}\] term of a geometric progression is 9 and \[{{4}^{th}}\] term is 4, then its \[{{7}^{th}}\] term is [MP PET 1996]

A. 6
B. 36
C. \[\frac{4}{9}\]
D. \[\frac{9}{4}\]
Answer» B. 36
4632.

If the roots of the cubic equation \[a{{x}^{3}}+b{{x}^{2}}+cx+d=0\] are in G.P., then

A. \[{{c}^{3}}a={{b}^{3}}d\]
B. \[c{{a}^{3}}=b{{d}^{3}}\]
C. \[{{a}^{3}}b={{c}^{3}}d\]
D. \[a{{b}^{3}}=c{{d}^{3}}\]
Answer» B. \[c{{a}^{3}}=b{{d}^{3}}\]
4633.

If \[{{\log }_{x}}a,\ {{a}^{x/2}}\] and \[{{\log }_{b}}x\] are in G.P., then \[x=\]

A. \[-\log ({{\log }_{b}}a)\]
B. \[-{{\log }_{a}}({{\log }_{a}}b)\]
C.  \[{{\log }_{a}}({{\log }_{e}}a)-{{\log }_{a}}({{\log }_{e}}b)\]
D.   \[{{\log }_{a}}({{\log }_{e}}b)-{{\log }_{a}}({{\log }_{e}}a)\]
Answer» D.   \[{{\log }_{a}}({{\log }_{e}}b)-{{\log }_{a}}({{\log }_{e}}a)\]
4634.

The first and last terms of a G.P. are \[a\] and \[l\] respectively; \[r\] being its common ratio; then the number of terms in this G.P. is

A.   \[\frac{\log l-\log a}{\log r}\]
B. \[1-\frac{\log l-\log a}{\log r}\]
C.   \[\frac{\log a-\log l}{\log r}\]
D. \[1+\frac{\log l-\log a}{\log r}\]
Answer» E.
4635.

The \[{{20}^{th}}\] term of the series \[2\times 4+4\times 6+6\times 8+.......\]will be [Pb. CET 1988]

A. 1600
B. 1680
C. 420
D. 840
Answer» C. 420
4636.

If the \[{{5}^{th}}\] term of a G.P. is \[\frac{1}{3}\] and \[{{9}^{th}}\] term is \[\frac{16}{243}\], then the \[{{4}^{th}}\] term will be [MP PET 1982]

A. \[\frac{3}{4}\]
B. \[\frac{1}{2}\]
C. \[\frac{1}{3}\]
D. \[\frac{2}{5}\]
Answer» C. \[\frac{1}{3}\]
4637.

If the \[{{p}^{th}}\],\[{{q}^{th}}\] and \[{{r}^{th}}\]term of a G.P. are \[a,\ b,\ c\] respectively, then \[{{a}^{q-r}}.\ {{b}^{r-p}}.\ {{c}^{p-q}}\] is equal to [Roorkee 1955, 63, 73; Pb. CET 1991, 95]

A. 0
B. 1
C. \[abc\]
D. \[pqr\]
Answer» C. \[abc\]
4638.

If \[x,\ y,\ z\] are in G.P. and \[{{a}^{x}}={{b}^{y}}={{c}^{z}}\], then [IIT 1966, 68]

A. \[{{\log }_{a}}c={{\log }_{b}}a\]
B. \[{{\log }_{b}}a={{\log }_{c}}b\]
C. \[{{\log }_{c}}b={{\log }_{a}}c\]
D. None of these
Answer» C. \[{{\log }_{c}}b={{\log }_{a}}c\]
4639.

If \[a,\,b,\,c\] are in G.P., then

A. \[a({{b}^{2}}+{{a}^{2}})=c({{b}^{2}}+{{c}^{2}})\]
B. \[a({{b}^{2}}+{{c}^{2}})=c({{a}^{2}}+{{b}^{2}})\]
C. \[{{a}^{2}}(b+c)={{c}^{2}}(a+b)\]
D. None of these
Answer» C. \[{{a}^{2}}(b+c)={{c}^{2}}(a+b)\]
4640.

If the \[{{(r+1)}^{th}}\] term in the expansion of \[{{\left( \sqrt[3]{\frac{a}{\sqrt{b}}}+\sqrt{\frac{b}{\sqrt[3]{a}}} \right)}^{21}}\] has the same power of a and b, then the value of r is

A. 9
B. 10
C. 8
D. 6
Answer» B. 10
4641.

The middle term in the expression of \[{{\left( x-\frac{1}{x} \right)}^{18}}\] is   [Karnataka CET 2005]

A. \[^{18}{{C}_{9}}\]
B. \[{{-}^{18}}{{C}_{9}}\]
C. \[^{18}{{C}_{0}}\]
D. \[{{-}^{18}}{{C}_{10}}\]
Answer» C. \[^{18}{{C}_{0}}\]
4642.

The middle term in the expansion of \[{{\left( x+\frac{1}{2x} \right)}^{2n}}\], is  [MP PET 1995]

A. \[\frac{1.3.5....(2n-3)}{n!}\]
B. \[\frac{1.3.5....(2n-1)}{n!}\]
C. \[\frac{1.3.5....(2n+1)}{n!}\]
D. None of these
Answer» C. \[\frac{1.3.5....(2n+1)}{n!}\]
4643.

The coefficient of \[{{x}^{n}}\]in expansion of \[(1+x)\,{{(1-x)}^{n}}\] is  [AIEEE 2004]

A. \[{{(-1)}^{n-1}}n\]
B. \[{{(-1)}^{n}}(1-n)\]
C. \[{{(-1)}^{n-1}}{{(n-1)}^{2}}\]
D. \[(n-1)\]
Answer» C. \[{{(-1)}^{n-1}}{{(n-1)}^{2}}\]
4644.

The coefficient of \[{{t}^{24}}\] in the expansion of \[{{(1+{{t}^{2}})}^{12}}(1+{{t}^{12}})\,(1+{{t}^{24}})\] is [IIT Screening 2003]

A. \[^{12}{{C}_{6}}+2\]
B. \[^{12}{{C}_{5}}\]
C. \[^{12}{{C}_{6}}\]
D. \[^{12}{{C}_{7}}\]
Answer» B. \[^{12}{{C}_{5}}\]
4645.

The coefficient of \[{{x}^{4}}\] in the expansion of \[{{(1+x+{{x}^{2}}+{{x}^{3}})}^{n}}\] is                                [MNR 1993; RPET 2001; DCE 1998]

A. \[^{n}{{C}_{4}}\]
B. \[^{n}{{C}_{4}}{{+}^{n}}{{C}_{2}}\]
C. \[^{n}{{C}_{4}}+{{\,}^{n}}{{C}_{2}}+\,{{\,}^{n}}{{C}_{4}}{{.}^{n}}{{C}_{2}}\]
D. \[^{n}{{C}_{4}}+{{\,}^{n}}{{C}_{2}}+{{\,}^{n}}{{C}_{1}}.{{\,}^{n}}{{C}_{2}}\]
Answer» E.
4646.

If coefficient of \[{{(2r+3)}^{th}}\] and \[{{(r-1)}^{th}}\] terms in the expansion of \[{{(1+x)}^{15}}\] are equal, then value of r is [RPET 1995, 2003; UPSEAT 2001]

A. 5
B. 6
C. 4
D. 3
Answer» B. 6
4647.

The greatest coefficient in the expansion of \[{{(1+x)}^{2n+1}}\] is [RPET 1997]

A. \[\frac{(2n+1)\,!}{n!(n+1)!}\]
B.   \[\frac{(2n+2)!}{n!(n+1)!}\]
C.   \[\frac{(2n+1)!}{{{[(n+1)!]}^{2}}}\]
D.   \[\frac{(2n)!}{{{(n!)}^{2}}}\]
Answer» B.   \[\frac{(2n+2)!}{n!(n+1)!}\]
4648.

The interval in which  x must lie so that the greatest term in the expansion of \[{{(1+x)}^{2n}}\]has the greatest coefficient, is

A. \[\left( \frac{n-1}{n},\frac{n}{n-1} \right)\]
B. \[\left( \frac{n}{n+1},\frac{n+1}{n} \right)\]
C. \[\left( \frac{n}{n+2},\frac{n+2}{n} \right)\]
D. None of these
Answer» C. \[\left( \frac{n}{n+2},\frac{n+2}{n} \right)\]
4649.

If n is even positive integer, then the condition that the greatest term in the expansion of \[{{(1+x)}^{n}}\]may have the greatest coefficient also, is

A. \[\frac{n}{n+2}<x<\frac{n+2}{n}\]
B. \[\frac{n+1}{n}<x<\frac{n}{n+1}\]
C. \[\frac{n}{n+4}<x<\frac{n+4}{4}\]
D. None of these
Answer» B. \[\frac{n+1}{n}<x<\frac{n}{n+1}\]
4650.

The greatest term in the expansion of \[\sqrt{3}{{\left( 1+\frac{1}{\sqrt{3}} \right)}^{20}}\]is

A. \[\frac{25840}{9}\]
B. \[\frac{24840}{9}\]
C. \[\frac{26840}{9}\]
D. None of these
Answer» B. \[\frac{24840}{9}\]