Physics
A nucleus of an atom consists of 146 neutrons and 95 protons. It decays after emitting an alpha particle. How many protons and neutrons are left in the nucleus after an alpha emission?
- protons = 93, neutrons = 142
- protons = 95, neutrons = 144
- protons = 93, neutrons = 144
- protons = 95, neutrons = 142
Related Questions
Heat capacity of a body is the :
- energy needed to melt a body without change in its temperature
- energy needed to raise the temperature of a body by 1°C
- increase in volume of the body when its temperature increases by 1°C
- total amount of internal energy that is constant
The amount of heat energy required to melt a given mass of a substance at its melting point without any rise in its temperature is called as the :
- specific heat capacity
- specific latent heat of fusion
- latent heat of fusion
- specific latent heat of freezing
Complete the following by choosing the correct answers from the bracket :
(a) A …………… [class I/class II/Class III] lever will always have M.A. > 1.
(b) In a block and tackle system, increase in the weight of the movable block …………… [decreases/does not affect/increases] the efficiency of the pulley system.
(c) If the mass as well as the velocity of a body is doubled then the kinetic energy of the body …………… [is doubled/becomes eight times/becomes four times] the initial kinetic energy.
(d) Unit of power used in mechanical engineering is …………… . [watt/horse power/erg per second]
(e) Two copper wires can have the different …………… [resistivity/resistance] but will have same …………… .[resistance/resistivity]
Draw a graph of potential energy vs height for a body thrown vertically upwards. [Assume no friction is present.]