List of practice Questions

A square wire of each side l carries a current I. The magnetic field at the mid point of the square is

A pair of stationary and infinitely long bent wires are placed in the x-y plane as shown in figure. The wires carry currents of 10A each as shown. The segments L and M are along the x-axis. The segments P and Q are parallel to the y-axis such that OS = OR = 0.02m. Find magnitude and direction of the magnetic induction at the origin O.
A pair of stationary and infinitely long bent wires are placed in the x-y plane as shown in figure

A number of bullets are fired horizontally with different velocities from the top of a tower they reach the ground
A mild steel wire of length 2L and cross-sectional area A is stretched, well within elastic limit, horizontally between two pillars as shown in the figure. A mass M is suspended from the mid-point of the wire. Strain in the wire is
A liquid drop of diameter D breaks up into 27 drops. Find the resultant change in energy
A force of $- F \hat{k}$ acts on $O$, the origin of the coordinate system. The torque about the point $(1,-1)$ is
A convex lens forms a real image of the object when the lens is at a distance of 1 m form the object. The size of the image is 3 times that of the object. The position of the object and the screen are kept fixed but the distance of lens from the object is doubled. The image is now one half of the size of the object, the focal length of the lens is
A class is composed of two brothers and six other boys. In how many ways can all the boys be seated at a round table so that the two brothers are not seated besides each others ?
A blacksmith fixes iron ring on the rim of the wooden wheel of bullock cart . the diameter of the rim and the iron ring are 5.243 m and 5.231 m respectively at $27^{\circ} C$ . The temperature should the ring be heated so as to fit the rim of the wheel?
A body is placed on rough $\left(\mu=\frac{1}{3\sqrt{3}}\right)$ inclined plane. $A$ force $F$ is needed to stop this body to slide downward. $A$ force $2F$ is needed so that the body is just about to move upwards. Slope of inclined plane is
A charged particle q is placed at the centre O of cube of length L (A B C D E F G H). Another same charge q is placed at a distance L from O. Then the electric flux through ABCD is
The number of ways in which $5$ ladies and $7$ gentlemen can be seated in a round table so that no two ladies sit together, is
What is the “misadventure” that William Douglas speaks about?
Draw a circle and two lines parallel to a given line such that one is a tangent and the other, a secant to the circle.
Why is a normal eye not able to see clearly the objects placed closer than 25 cm?
Sarfaraz and Khalid got a big packet of candy each as their birthday gifts. Sarfaraz’s packet has 90 gems and the numbers of yellow, pink, and blue gems are three prime numbers. The number of yellow gems is the least and the number of blue gems is highest. Khalid’s packet has 78 gems and the numbers of yellow, pink, and blue gems are three consecutive even numbers in the same order. The number of blue gems is the highest among the three even numbers. Find the LCM of the minimum number of blue gems in Sarfaraz’s packet and the number of yellow gems in Khalid’s packet.
Which of these terms is not used in a linear programming problem?

The Art Institute of Chicago has recreated the famous painting "the bedroom" by Vincent van Gogh.
Carefully observe the image which will disappear after 30 seconds and answer the two following questions. The image cannot be viewed again.
famous painting the bedroom

The sale of electric bulbs on different days of a week is shown below : 
The sale of electric bulbs on different days of a week
Observe the pictograph and answer the following questions :
  1. How many bulbs were sold on Friday?
  2. On which day were the maximum number of bulbs sold?
  3. On which of the days same number of bulbs were sold?
  4. On which of the days minimum number of bulbs were sold?
  5. If one big carton can hold 9 bulbs. How many cartons were needed in the given week?
Simplify and solve the linear equation \(15(y-4)-2(y-9)+5(y+6)=0\)
A point dipole with dipole moment, $\vec{p} = p_0 \hat{k}$ , is kept at the origin. An external electric field given by, $\vec{E} = E_0 ( 2\hat{i} - 3\hat{j} + 4\hat{k})$ , is applied on it. Which one of the following statements is true ?
The coefficient of linear expansion of a metal rod is $12 \times 10^{-6} / ^{\circ}C$ , its value in per its value in per $^{\circ}F$
Answer the following : 
  1. You are given a thread and a metre scale. How will you estimate the diameter of the thread ? 
  2. A screw gauge has a pitch of 1.0 mm and 200 divisions on the circular scale. Do you think it is possible to increase the accuracy of the screw gauge arbitrarily by increasing the number of divisions on the circular scale ? 
  3. The mean diameter of a thin brass rod is to be measured by vernier calipers. Why is a set of 100 measurements of the diameter expected to yield a more reliable estimate than a set of 5 measurements only ?
How did this experience affect him?
Simplify and solve the linear equation \(3(t-3)=5(2t+1)\)