HSC Science (Electronics) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions for Physics

The instrument which can measure terminal potential difference as well as electromotive force (emf) is ______ 

What is the SI unit of potential gradient?

State any one use of a potentiometer.

A voltmeter has a resistance of 100 Ω. What will be its reading when it is connected across a cell of emf 6 V and internal resistance 20 Ω? 

What are the disadvantages of a potentiometer over a voltmeter?

A cell of e.m.f 1.5V and negligible internal resistance is connected in series with a potential meter of length 10 m and the total resistance of 20 Ω. What resistance should be introduced in the resistance box such that the potential drop across the potentiometer is one microvolt per cm of the wire?  

The emf of a standard cell is 1.5V and is balanced by a length of 300 cm of a potentiometer with a 10 m long wire. Find the percentage error in a voltmeter that balances at 350 cm when its reading is 1.8 V.  

An ideal transformer has 100 turns in the primary and 250 turns in the secondary. The peak value of the AC is 28 V. The rms secondary voltage is nearest to ______ 

State the mathematical relation between a number of turns in the primary coil to a secondary coil in the step-up transformer. 

Distinguish between Step up and Step Down Transformer.

What is Transformer?

Explain step up and step down transformer?

The primary of a transformer has 40 turns and works on 100 V and 100 W. Find a number of turns in the secondary to step up the voltage to 400 V. Also calculate the current in the secondary and primary.

Describe the construction and working of a transformer with a neat labelled diagram.

According to De-Broglie, the waves are associated with ______ 

An electron is accelerated through a potential of 120 V. Find its de Broglie wavelength.

Calculate De Broglie's wavelength of the bullet moving with speed 90m/sec and having a mass of 5 gm. 

Explain De Broglie’s Hypothesis.

The radii of Bohr orbit are directly proportional to ______ 

According to Bohr's second postulate, the angular momentum of the electron is the integral multiple of `h/(2pi)`. The S.I unit of Plank constant h is the same as ______