MAH-MHT CET (PCM/PCB) entrance exam Question Bank Solutions for Physics

A conducting wire has length 'L₁' and diameter 'd₁'. After stretching the same wire length becomes 'L₂' and diameter 'd₂' The ratio of resistances before and after stretching is ______.

The energy of an electron having de-Broglie wavelength `λ` is ______.

(h = Plank's constant, m = mass of electron)

Two unknown resistances are connected in two gaps of a meter-bridge. The null point is obtained at 40 cm from left end. A 30 Ω resistance is connected in series with the smaller of the two resistances, the null point shifts by 20 cm to the right end. The value of smaller resistance Ω is ______.

In series LCR circuit R = 18 Ω and impedance is 33 Ω An rms voltage 220V is applied across the circuit. The ture power consumed in AC circuit is ______.

For a transistor,  α_dc and β_dc are the current ratios, then the value of `(beta_"dc"-delta_"dc")/(alpha_"dc".beta_"dc")` 

An electron of mass m has de-Broglie wavelength λ when accelerated through potential difference V. When proton of mass M, is accelerated through potential difference 9V, the de-Broglie wavelength associated with it will be ______. (Assume that wavelength is determined at low voltage)

The ratio of the forces between two charges placed at a certain distance apart in the air and by the same distance apart in a medium of dielectric constant K is ______.

Two point charges +2 C and +6 C repel each other with a force of 12 N. If a charge of -4 C is given to each of these charges, then the force now is ______.

In a p-n-p transistor circuit, the collector current is 10 mA. If 90% of the holes emitted from the emitter reach the collector, ______.

The reverse bias in a junction diode is changed from 8V to 13V, then the value of the current changes from 40μA to 60μA. The resistance of junction diode will be ______.

A conductor lies along the Z-axis at −1.5 ≤ Z ≤ 1.5 m and carries a fixed current of 10.0 A in −a_z​ direction as (see figure). For a field B = 3.0 × 10⁻⁴`"e"^(−0.2"x")`a_y ​T, find the power required to move the conductor at constant speed to x = 2.0 m, y = 0 in 5 × 10⁻³ s. Assume parallel motion along the x-axis.

A common emitter amplifier circuit built using an n-p-n transistor is shown in the figure. Its DC current gain is 300, R_C = 4 kΩ and V_CC = 20 V. What is the minimum base current for V_CE to reach saturation?

The base current in common emitter mode of the transistor changes by 10 µA. If the current gain of the transistor is 50, then change in collector current is ______.

The transfer ratio of a transistor is 50. The input resistance of the transistor when used in the CE configuration is 1K Ω. The peak value for an AC input voltage of 0.01 V of collector current is ______.

The current amplification factor for a transistor in its common emitter mode is 50. The current amplification factor in the common base mode of the transistor is ______.

Four charges equal to −Q are placed at the four a corners of a square and charge q is at its centre. If the system is in equilibrium, the value of q is ______.

For a gas, `"R"/"C"_"v"=0.4`, where R Is universal gas constant and C_v is the molar specific heat at constant volume. The gas is made up of molecules, which are ______

A diatomic gas undergoes adiabatic change. Its pressure 'P' and temperature 'T' are related as p ∝ T^x, where x is ______.

When a coil is connected to a D.C. source of e.m.f. 12 volt, then a current of 4 ampere flows in it. If the same coil is connected to a 12 volt, 25 cycle/s A.C sources, then the current flowing in it is 2.4 A. The self-inductance of the coil will be ______

Two rods of same material and volume having circular cross-section are subjected to tension T. Within the elastic limit, same force is applied to both the rods. Diameter of the first rod is half of the second rod, then the extensions of first rod to second rod will be in the ratio