If ten students are asked to measure the length of a piece of cloth up to a mm, using a metre scale, do you think their answers will be identical? Give reasons.

Your laboratory partner was given the task of measuring the length of a box (approx 5 in) as accurately as possible, using a metre stick graduated in milimeters. He supplied you with the following measurements: 12.65cm,12.6cm,12.65cm,12.655cm,126.55mm,12cm Give yours reason for rejecting each of the others.

Now , measure the length of a bench by means of the span of your hand . Ask your friends to do the same . Did each of you obtain the same measure for that bench ? What could be the reason ?

Answer the following questions : In a std. X Class , out of 40 students , 10 students use spectacles, 2 students have posotive power and 8 students have negative power of lenses in their spectacles. Answerthe following question : Give two possible reasons for the above defect in 8 students?

Read the following paragraph and answer the following questions given below it : Construction of a compound microscope : (i) Acompound microscope consists of a metal tube fitted with two convex lenses at the two ends. These lenses are called the objective lens ( the lens directed towards the object ) and the eyepiece ( the lens directed towards the eye ). Both the lenses are small in size , but the cross section of the objective lens has a short focal length . the focal length of the eyepiece is more than that of the objective lens . (ii) The metal tube is mounted on a stand . thr principal axes of the objective lens and the eyepiece are along the same line . The distance between the object and objective lens can be changed with a screw . It is possible to change the distance between the objective lens and the eyepiece. Working : (i) The object to be observed is illuminated and placed in front of the objective lens. slightly beyond the focal length of the objective lens. it's real , inverted and enlarged image is formed by the objective lens on the other side. (ii) This intermediate image lies with in the focal length of the eyepiece. It serves as an object for the eyepiece. The eyepiece works as a simple microscope . the final image is virtual, highly enlarged and inverted with respect to the original object . It can be formed at the minimum distance of distinct vision from the eyepiece . The final image is observed by keeping the eye close to the eyepiece. Use: This microscope is used to observe blood cells , microorganisms , etc. Where do you place the object to be observed with a compound microscope ?

A student measures the value of g with the help of a simple pendulum using the formula g = (4pi^(2)L)/(T^(2)) . He measures length L with a meter scale having least count 1 mm and finds it 98.0 cm . The time period is measured with the help of a watch of least count 0.1s . The time of 20 oscillations is found to be 40.4 s. The error Deltag in the measurment of g is (" in" m//s^(2)) .

A student measured the diameter of a small steel ball using a screw gauge of least count 0.001 cm . The main scale reading is 5 mm and zero of circular scale division coincides with 25 divisions above the reference level. If screw gauge has a zero error of -0.004 cm , the correct diameter of the ball is

Question based on paragraph Students were taken to observe the crop cultivation in a potato farm in Maharashtra. The students observed that the yield of crops in Mr. Shyam's potato farm was more than that in his neighbour Bharat’s potato farm. Mr. Shyam was using a different variety of the crop, which he suggests has been disease-free ever since he planted the seeds. Based on the above passage, answer the given question What type of crop do you think Mr. Shyam must be using?

Question based on paragraph Students were taken to observe the crop cultivation in a potato farm in Maharashtra. The students observed that the yield of crops in Mr. Shyam's potato farm was more than that in his neighbour Bharat’s potato farm. Mr. Shyam was using a different variety of the crop, which he suggests has been disease-free ever since he planted the seeds. Based on the above passage, answer the given question Do you know any superior variety of potato?

Read the given passage and answer the following questions: The home electrical connection consists of 'live','neutral' and 'earth wires. The 'live' and the 'neutral' wires have potential difference of 220 v. The earth ire is connected to ground. Due to a fault in the equipment or if the plastic coating on the 'live ' and the neutral wires gives away the two wires come in contact with each other and a large current flows through it producing heat . If any inflammable material (such as wood , cloth , plastic etc). exists around that place it can catch fire. Therefore a fuse wire is used as a precautionary measures. Name the two wires having potential difference of 220 v.

Read the given passage and answer the following questions: The home electrical connection consists of 'live','neutral' and 'earth wires. The 'live' and the 'neutral' wires have potential difference of 220 v. The earth ire is connected to ground. Due to a fault in the equipment or if the plastic coating on the 'live ' and the neutral wires gives away the two wires come in contact with each other and a large current flows through it producing heat . If any inflammable material (such as wood , cloth , plastic etc). exists around that place it can catch fire. Therefore a fuse wire is used as a precautionary measures. What is short circuit?