MHT - CET MCQ

In the case of NAND gate, if A and Bare in the inputs and Y is the output, then ______.

In a silicon transistor, a change of 7.89 mA in the emitter current if produces a change of 7.8 mA in the collector current, then the base current must change by ____________.

A common emitter amplifier is designed with n-p-n transistor (α = 0.99). The input impedance is 1 kΩ and the load is 10 kΩ. The voltage gain will be ______

Using Bohr's quantization condition, what is the rotational energy in the second orbit for a diatomic molecule. (I = moment of inertia of diatomic molecule, h = Planck's constant)

In Bohr's model of hydrogen atom, the period of revolution of the electron in any orbit is proportional to ______.

The energy (in eV) required to excite an electron from n = 2 to n = 4 state in hydrogen atom is ____________.

Which one of the following graphs represents the variation of photoelectric current (i) with intensity (I) of the incident light?

The work function of a photosensitive material is 4.0 eV. The longest wavelength of light that can cause photon emission from the substance is (approximately) ____________.

Photoelectrons emitted from a metallic surface are initially ____________.

In an a.c. circuit containing L, C, R is series, the ratio of true power to apparent power is (Z = impedance of the circuit, R = resistance, `phi` = phase difference between the r.m.s. values of current and e.m.f.) ____________.

The rms value of current in a 50 Hz AC circuit is 6 A. The average value of AC current over a cycle is ____________.

Alternating current of peak value `(2/pi)` ampere flows through the primary coil of transformer. The coefficient of mutual inductance between primary and secondary coil is 1 H. The peak e.m.f. induced in secondary coil is ______. (Frequency of a.c. = 50 Hz)

Consider a solenoid carrying supplied by a source with a constant emf containing iron core inside it. When the core is pulled out of the solenoid, the change in current will ______.

Relative permeability of nickel is 550, then its magnetic susceptibility will be ____________.

An electron moving in a circular orbit of radius r makes n rotations per second. The magnetic field produced at the centre has magnitude ____________.

The sensitivity of moving coil galvanometer is inversely proportional to ____________.

A straight wire of length 0.5 m and carrying current of 1.2A is placed in a uniform magnetic field of induction 2T. The magnetic field is perpendicular to the length of the wire. What is the force acting on the wire? sin 90° = 1

The resistances in left and right gap of a metrebridge are 20 `Omega` and 30 `Omega` respectively. When the resistance in the left gap is reduced to half its value, the balance point shifts by ______.

Kirchhoff's law of radiation proves that ______

What determines the conventional direction of the product of current and resistance while applying the Kirchhoff's law?

Which of the following molecules is a polar molecule?

Statement - 1: For practical purpose, the earth is used as a reference at zero potential in electrical circuits.

Statement - 2: The electrical potential of a sphere of radius R with charge Q uniformly distributed on the surface is given by `Q/(4piepsilon_0R)`.

Band width for red light of wavelength 6600 Å is 0.42 mm. If red Light is replaced by blue light of wavelength 4400 Å, then the change m bandwidth will be ____________.

A plane wavefront is an incident on a water surface at an angle of incidence 60° then it gets refracted at 45°. The ratio of the width of incident wavefront to that of refracted wavefront will be ______

`[sin pi/4 = cos pi/4 = 1/sqrt2, sin60^circ = sqrt3/2, cos60^circ = 1/2]`

In a stationary wave all particles ______

In case of vibrating string, the frequency of the fifth harmonic is equal to frequency of the ____________.

Two identical samples of a gas are allowed to expand (i) isothermally (ii) adiabatically. Work done is ____________.

Temperatures of two stars are in the ratio 3 : 2. If wavelength of maximum intensity of first star is 4500 Å, the corresponding wavelength for second star is ______.

Half part of an ice block is covered with black cloth and rest half is covered with white cloth and then it is kept in sunlight. After some time, clothes are removed to see the melted ice. Which of the following statements is correct?

Reynold's number is less for ______.

A particle of mass m is rotating in a plane in a circular path of radius r. Its angular momentum is L. The centripetal force acting on the particle is ______.

Consider the junction diode as ideal. The value of current flowing through AB is ______.

Where should a person stand in front of a concave mirror of radius of curvature 20 cm to get a real image of his own, 2 times larger?

The pitch of the whistle of an engine appears to drop to`(5/6)^"th"` of original value when it passes a stationary observer. If the speed of sound in air is 350 m/s then the speed of engine is ____________.

If a body weighing 40 kg is taken inside the earth to a depth to radius of the earth, then `1/8`th the weight of the body at that point is ______.

For regular shapes of the small body, which of the following statement is true?

A particle is moving along the circular path of radius 'r' with velocity 'v'. The magnitude of average acceleration after half revolution is ______.

Figure shows the displacement-time graph of a particle moving along x-axis.