HSC Science (General) १२ वीं कक्षा - Maharashtra State Board Question Bank Solutions for Physics

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. 

What are Secondary sources? State Huygens’ Principle.

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 ______ 

For a transistor β =75 and I_E = 7.5 mA. The value of α is ______ 

In a transistor amplifier, I_C = 5.5 mA , I_E = 5.6 mA. The current amplification factor β is ______ 

Draw the circuit symbol of the PNP transistor. 

For a transistor I_C = 15 mA, I_B = 0.5 mA. What is the current amplification factor?  

Explain the working of the PNP transistor? 

Draw the circuit symbol for NPN and PNP transistors. What is the difference in the Emitter, Base, and Collector regions of a transistor?