What are the advantages of the null-point method in a Wheatstone bridge ? What additional measurements would be required to calculate `R -unknown` by any other method ?

What are methods/measures to control druge abuse?

What happens if the galvanometer and cell are interchanged at the balance point of the bridge ? Would the galvanometer show any current .

Take a long rubber band and cut it at one point . At one of its ends tie a clean washed stone or a 50g weight as shown in figure Now hold the other end of the rubber band and make a mark there . Keep the stone hanging in air and measure the length of the rubber band from the stone to the mark made earlier . now take water in a pot and hold the rubber band at such a height that the stone sinks in it . again measure the length of the rubber band up to the mark . : What could be the reason for a shorter length of the rubber band in water ? :

Take a long rubber band and cut it at one point . At one of its ends tie a clean washed stone or a 50g weight as shown in figure Now hold the other end of the rubber band and make a mark there . Keep the stone hanging in air and measure the length of the rubber band from the stone to the mark made earlier . now take water in a pot and hold the rubber band at such a height that the stone sinks in it . again measure the length of the rubber band up to the mark . : What is observed ?:

The measurement of an unknown resistance R is to be carried out using Wheatstone's bridge. Two students perform an experiment in two ways. The first student R_2 = 10 Omega and R_1 = 5 Omega the other student takes R_2 = 1000 Omega and R_1 = 500 Omega . In the standard arm ,both take R_3 = 5 Omega . Both find R = [R_2/R_1] R_3 = 10 Omega within errors

In the figure , O is the center of the circle. From point R, seg RM and seg RN are tangent segments touching the circle at M and N. If OR = 10cm and radius of the circle = 5 cm, then (i) What is the length of each tanget segment ? (iii) What is the measure of /_MRO ? (iii) Whatis the measure of /_ MRN ?

Resistances P = 10 Omega , Q = 15 Omega , R = 25 Omega and S = 50 Omega are connected in the arms AB,BC,CD and DA respectively of a Wheatstone's network ABCD . The cell is connected between points A and C . What resistance has to be connected in parallel with 'S' to balance the network ?

Paragraph based Questions : Read the paragraph and answer the questions given below : Remediation is the process of removing dangerous or poisonous substances from the environment, or limiting the effect that they have on it. When any biological organism is used for remediation, it is called bioremediation. When plant species are used for the purpose of remediation, it is called phytoremediation. When any microbes are used then it is named as microbial remediation. The methods of such remediation have helped to clean the environment from toxic effluents, especially sewage and crude oi]. Dr. Anand Chakraborty, a scientist of Indian origin, has worked on Pseudomonas aeruginosa which have reduced the crude oil films into carbon dioxide and water. What is the meaning of remediation?

Answer the following questions:Make two sufficiently long, identical tubes out of a cardboard. Arrange them on a table, in front of a wall as shown in figure . Place a clock near the end of one of the tubes and try to hear the ticking of the clock at the end of the other tube by placing your ear there. Adjust the angles of the two tubes till you can hear the sound very clearly Measure the angle of incidence theta_1 and the angle of reflection theta_2 . Try to see if they are related in any way. In the experiment, what will happen if you lift one of the tubes to some height?

Statement-1 : In a Meter Bridge experiment, null point for an unknown resistance is measured. Now, the unknown resistance is put inside an enclosure maintained at a higher temperature. The null point can be obtained at the same point as before by decreasing the value of the standard resistance. Statement-2 : Resistance of metal increases with increase in temperature.