NEB Question Browser

Why and how did Laplace correct Newton's formula for velocity of sound in air?

What is the displacement amplitude for a sound wave having a frequency of 100 Hz and a pressure amplitude of 10 Pa? (Speed of sound in air is 340 m/s and density of air is 1.29 kg/m³)

What property of a p–n junction diode enables its use in rectifiers?

Explain the construction and working of a full wave rectifier.

Write the truth table of two inputs NAND gate.

Define one curie.

Obtain a relation between half life and decay constant.

The half-life of a radioactive isotope is 10 days. What is the percentage of the sample remaining after 25 days?

Draw a phase diagram for the circuit.

If L = 0.5 H and C = 20 μF, find the resonant frequency of the circuit.

The critical angle of water is 48°. What is its polarizing angle?

Diffraction grating is better than Young's double slit for measuring the wavelength of a monochromatic light. Explain.

Calculate impedance of the circuit.

Give an application of resonating a.c. circuit.

Derive the equation: N = N₀e⁻λt for radioactive process where symbols have their usual meanings.

Why is 220 V a.c. more dangerous than 220 V d.c.? Explain.

What is natural radioactivity?

What is the use of X-rays in Millikan's oil drop experiment?

Guitar string of length 1.5 m is made of steel of density 7800 kg/m³ and Young's modulus 2 × 10¹¹ N/m². It produces an elastic strain of 1% in the string. Calculate:
i) Stress developed in the string.
ii) Frequency of second mode of vibration.

The given figure shows standing wave formed in an open organ pipe.
i) Which mode of vibration is shown? [1]
ii) Obtain frequency of vibration for this mode. [1]