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

On what factors does the potential gradient of the wire depend?

A vehicle is moving on a circular track whose surface is inclined towards the horizon at an angle of 10°. The maximum velocity with which it can move safely is 36 km / hr. Calculate the length of the circular track. [π = 3.142]

State the advantages of potentiometer over voltmeter.

The width of plane incident wavefront is found to be doubled on refraction in denser medium. If it makes an angle of 65° medium. with the normal, calculate the refractive index for the denser medium.

What should be tension applied to a wire of length 1 m and mass 10 gram, if it has to vibrate with fundamental frequency of 50 Hz?

Derive an expression for e.m.f. and current in terms of turns ratio

Represent Radioactive Decay curve using relation `N = N_o e^(-lambdat)` graphically

Define radius of gyration.

A transformer converts 240 V AC to 60 V AC. The secondary has 75 turns. The number of turns in primary are _______.

(A) 600

(B) 500

(C) 400

(D) 300

SI unit of potential gradient is _______.

(a) V cm

(b) `V/"cm"`

(c) Vm

(d) `V/m`

Calculate the internal energy at 298K for the formation of one mole of ammonia, if the enthalpy change at constant pressure is – 42.0 kJ mol^-1.

(Given: R = 8.314 J K^-1 mol^-1)

State the working principle of a potentiometer. With the help of the circuit diagram, explain how a potentiometer is used to compare the emf's of two primary cells. Obtain the required expression used for comparing the emfs.

An alternative voltage given by V = 140 sin 314t is connected across a pure resistor of 50 Ω. Find

1. The frequency of the source.
2. The rms current is through the resistor.

What happens to a ferromagnetic substance heated above Curie temperature ?

The susceptibility of magnesium at 300 K is 1.2 x 10 ^-5 . What will be its susceptibility at 200 K.

Define binding energy and obtain an expression for binding energy of a satellite revolving in a circular orbit round the earth.

State Hooke’s law. Define the elastic limit and modulus of elasticity.

When a resistor of 5Ω is connected across the cell, its terminal potential difference is balanced by 150 cm of potentiometer wire and when a resistance of 10 Ω is connected across the cell, the terminal potential difference is balanced by 175 cm same potentiometer wire. Find the balancing length when the cell is in open circuit and the internal resistance of the cell.

Assuming expression for impedance in a parallel resonant circuit, state the conditions for parallel resonance. Define resonant frequency and obtain an expression for it.