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

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Two identical springs of constant k are connected, first in series and then in parallel. A metal block of mass m is suspended from their combination. The ratio of their frequencies of vertical oscillations will be in a ratio

A 15.0 μF capacitor is connected to a 220 V, 50 Hz source. Find the capacitive reactance and the current (rms and peak) in the circuit. If the frequency is doubled, what will happen to the capacitive reactance and the current?

A capacitor of 100 μF, a coil of resistance 50Ω, and an inductance 0.5 H are connected in series with a 110 V-50Hz source. Calculate the rms value of current in the circuit.

Find the capacity of a capacitor which when put in series with a 10Ω resistor makes the power factor equal to 0.5. Assume an 80V-100Hz AC supply.

Find the time required for a 50 Hz alternating current to change its value from zero to the rms value.

State the characteristics of progressive waves.

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Polychromatic (containing many different frequencies) radiation is used in an experiment on the photoelectric effect. The stopping potential ______.

What is the photoelectric effect?

Can microwaves be used in the experiment on photoelectric effect?

Is it always possible to see the photoelectric effect with a red light?

Explain the inverse linear dependence of stopping potential on the incident wavelength in a photoelectric effect experiment.

Draw the circuit diagram of a half-wave rectifier. Explain its working. What is the frequency of ripple in its output?

Draw a neat diagram of a full-wave rectifier and explain it’s working.

Using the energy conservation, derive the expressions for the minimum speeds at different locations along a vertical circular motion controlled by gravity. Is zero speed possible at the uppermost point? Under what condition/s?

Using energy conservation, along a vertical circular motion controlled by gravity, prove that the difference between the extreme tensions (or normal forces) depends only upon the weight of the objects.

Two charges of magnitudes −4Q and + 2Q are located at points (2a, 0) and (5a, 0) respectively. What is the electric flux due to these charges through a sphere of radius 4a with its centre at the origin?

Answer in brief.

The amplitude of a wave is represented by y = 0.2 sin 4π `["t"/0.08-"x"/0.8]` in SI units. Find (a) wavelength, (b) frequency, and (c) amplitude of the wave.

An electron in an atom is revolving around the nucleus in a circular orbit of a radius of 5.3 x 10^-11 m, with a speed of 2 x 10⁶ m/s. Find the resultant orbital magnetic moment and angular momentum of the electron. [e = 1.6 x 10^-19 C, m_e= 9.1 x 10^-31 kg]

If the effective current in a 50 cycle AC circuit is 5 A, what is the peak value of current? What is the current 1/600 after if was zero?