(English Medium) ICSE Class 10 - CISCE Question Bank Solutions

A switch must be connected in the ______.

What is nucleus of an atom? Compare its size with that of the atom. Name its constitutents. How is the number of these constituents determined by the atomic number its atomic model.

Name two radioactive substances.

A radioactive substance is oxidized. What changes would you expect to take place in the nature of radioactivity? Explain your answer.

A radioactive source emits three types of radiations.

Name the radiation which has the highest ionizing power.

What happens to the position of an element in the periodic table when it emits an alpha particle 

A certain nucleus A (mass number 238 and atomic number 92) is radioactive and becomes a nucleus B (mass number 234 and atomic number 90) by the loss of one particle.

What particle was emitted?

A nucleus is  \[\ce{^24_11 Na}\]  β-radioactive.

Write the equation represent β-decay.

An element P disintegrates by α - -emission and the new element suffers two further disintegrations, both by β -emission, to form an element Q. Explain the fact that P and Q are the isotopes.

During the emission of a beta particle, the ______ number remains same.

State three safety precautions that you would take while handling the radioactive substances.

Why should a radioactive substance not be touched by hands?

There is no gain in mechanical advantage in the case of a single fixed pulley. Explain, why the pulley is then used?

In the case of a block and tackle arrangement, the mechanical advantage increases with the number of pulleys. Explain.

State two reasons, why the efficiency of a pulley system is not 100 percent?

A type of single pulley is very often used as a machine even though it does not give any gain in mechanical advantage. Name the type of pulley used.

A type of single pulley is very often used as a machine even though it does not give any gain in mechanical advantage. For what purpose is such a pulley used?

What is the relation between the mechanical advantage and the number of strands of string used to support the load, in a ‘block and tackle’ set-up?

What is a block and tackle system of pulleys? What precautions would you observe while rounding the string so that the effort is applied in the downward direction?

In the alongside the figure of two pulleys shown a system in which one pulley is fixed and the other is movable. What is the velocity ratio of the system?
An effort of 600 N is needed to lift a weight of 1000 N. What are the mechanical advantage and efficiency of the pulley system?