HSC Science (Computer Science) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions

Two wheels of the moment of inertia 4 kgm² rotate side by side at the rate of 120 rev/min and 240 rev/min respectively in the opposite directions. If now both the wheels are coupled by means of a weightless shaft so that both the wheels rotate with a common angular speed. Calculate the new speed of rotation.  

The velocity of the three molecules is 2 km s^-1, 4 km s^-1, 6 km s^-1. Find (i) mean square velocity (ii) root mean square velocity. 

Which of the following is correct, when the energy is transferred to a system from its environment?

Which of the following system freely allows the exchange of energy and matter with its environment? 

What is the energy associated with the random, disordered motion of the molecules of a system called as?

Define heat.

What is the internal energy of the system, when the amount of heat Q is added to the system and the system does not do any work during the process?

When does a system lose energy to its surroundings and its internal energy decreases? 

A system releases 100 kJ of heat while 80 kJ of work is done on the system. Calculate the change in internal energy.

Explain given cases related to energy transfer between the system and surrounding –

1. energy transferred (Q) > 0
2. energy transferred (Q) < 0
3. energy transferred (Q) = 0 

Explain the different ways through which the internal energy of the system can be changed. 

One gram of water (1 cm³) becomes 1671 cm³ of steam at a pressure of 1 atm. The latent heat of vaporization at this pressure is 2256 J/g. Calculate the external work and the increase in internal energy. 

A cylinder containing one gram molecule of the gas was compressed adiabatically until its temperature rose from 27°C to 97°C. Calculate the work done and heat produced in the gas (𝛾 = 1.5).

derive the relation between the change in internal energy (∆U), work is done (W), and heat (Q). 

State law of length.

What are forced vibrations? 

Show that even as well as odd harmonics are present as an overtone in modes of vibration of the string. 

A pair of the adjacent coil has a mutual inductance of 1.5 H. If the current in one coil varies from 0 to 20 A in 0.5 s, what is the change of flux linked with the other coil. 

Define mutual inductance.

In a common base configuration, the transistor has an emitter current of 10 mA and a collector current of 9.8 mA. The value of base current is ______