List of practice Questions

Two tiny spheres carrying charges $1.8 \, \mu C$ and $2.8 \, \mu C$ are located at $40\, cm$ apart. The potential at the mid-point of the line joining the two charges is
Van de Graaff generator is used to
What happens when charge is placed on a soap bubble ?
What is the angle between electric field and equipotential surface?
What is the area of the plates of a 3F parallel plate capacitor, if the separation between the plates is 5 mm ?
Which among the following is an example of polar molecule?
Which of the following statements is/are true about the principle of Van de Graaff generator?
Which of the following statements is true about the relation between electric field and potential?
Work done in moving a charge between any two points in an electric field is independent of the path followed by the charge, between these points. Electrostatic force is a non conservative force.
The average weight of $25$ boys was calculated to be $78.4\, kg$. It was later discovered that one weight was misread as $69$ kg instead of $96 \,kg$. The correct average is
The mean and standard deviation of $100$ observations were calculated as $40$ and $5.1$, respectively by a student who took by mistake $50$ instead of $40$ for one observation. Find the correct standard deviation.
The mean deviation from the median of the following set of observations 5, 3, 9, 12, 3, 10, 12, 21, 18, 12, 21 is
The mean marks of 120 students is 20. It was later discovered that two marks were wrongly taken as 50 and 80 instead of 15 and 18. The correct mean of marks is
The mean of $100$ observations is $50$ and their standard deviation is $5$. The sum of all squares of all the observations is
The mean of 12 numbers is 24. If 5 is added in every number, the new mean is
The mean of $5$ observations is $4.4$ and their variance is $8.24$. If three of the observations are $1$, $2$ and $6$, find the other two observations.
The mean of the first n terms of the A.P. (a + d) + (a + 3d) + (a + 5d) + .... is
The mean of the given data is $30$. If total data is $70$, then missing numbers are
The mean of two samples of size 200 and 300 were found to be 25, 10 respectively. Their standard deviations were 3 and 4 respectively. The variance of combined sample of size 500 is
The mean weight of a group of 10 items is 28 and that of another group of n items is 35. The mean of combined group of 10 + n items is found to be 30. The value of n is
The most stable measure of central tendency is
$0.92 \,g$ of an organic compound was analysed by combustion method. The mass of the $U$-tube increased by $1.08 \,g$. What is the percentage of hydrogen in the compound?
$1$-Butene and cyclobutane show
59 g of an amide obtained from a carboxylic acid, RCOOH, upon heating with alkali liberated 17 g of ammonia. The acid is
A compound with molecular formula $C_4H_4O$ has all the four carbon atoms and the oxygen atom inthe ring. It also has two double bonds. The compound is