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

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

When the number of turns in a coil is tripled without any change in the length of the coil, its self-inductance ______

The coefficient of self-inductance of a solenoid is 0.20 mH. If a core of soft iron of relative permeability 900 is inserted, then the coefficient of self-inductance will become nearly ______

If 'C_p' and 'C_v' are molar specific heats of an ideal gas at constant pressure and volume respectively. If 'λ' is the ratio of two specific heats and 'R' is universal gas constant then 'C_p' is equal to ______.

50 g of copper is heated to increase its temperature by 10° C. If the same quantity of heat is given to 5 g water, the rise in its temperature is [Specific heat of copper = 420 joule-kg^-1 °C^-1 , specific heat of water = 4200 joule-kg^-I °C^-1]

Which of the following substances (A, B and C) has the highest specific beat?

Two uniform brass rods A and B of length land 2l and radii 2r and r respectively are heated to the same temperature. The ratio of the increase in the volume ofB to that of A is ____________.

If same current 'I' is flowing through two parallel wires, separated by the distance 'b' in air, then force acting per unit length of wires will be `(mu_0= "permeability of free space")`____________.

The magnetic potential energy stored in a certain inductor is 15 mJ, when the current in the inductor is 40 mA. This inductor is of inductance ____________.

When a capacitor connected with coil is completely discharged, then ____________.