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In a p-n junction diode, the change in temperature due to heating:
If a body is moving in a circle of radius $r$ with a constant speed $v$, its angular velocity is:
In an astronomical telescope in normal adjustment, a straight black line of length $L$ is drawn on the inside part of the objective lens. The eye-piece forms a real image of this line. The length of this image is $l$. The magnification of the telescope is:
Which set of colours would be observed in the air under the conditions depicted in the figure?
In total internal reflection when the angle of incidence is equal to the critical angle for the pair of media in contact, what will be the angle of refraction?
The ratio of contributions made by the electric field and magnetic field components to the intensity of an electromagnetic wave is : (c = speed of electromagnetic waves)
The input signal given to a CE amplifier having a voltage gain of 150 is $V_i = 2\cos(15t + \frac{\pi}{3})$. The corresponding output signal will be:
Taking into account of the significant figures, what is the value of $9.99 \text{ m} - 0.0099 \text{ m}$?
Rain is falling vertically downward with a speed of $35 \text{ m/s}$. The wind starts blowing after some time with a speed of $12 \text{ m/s}$ in the east to the west direction. The direction in which a boy standing at the place should hold his umbrella is:
The figure shows a logic circuit with two inputs $A$ and $B$ and the output $C$. The voltage waveforms across $A$, $B$ and $C$ are as given. The logic circuit gate is:
Two amplifiers of voltage gain $20$ each, are cascaded in series. If $0.01\text{ V}$ a.c. input signal is applied across the first amplifier, the output a.c. signal of the second amplifier in volts is:
A ray of light traveling in a transparent medium of refractive index $\mu$ falls on a surface separating the medium from the air at an angle of incidence of $45^{\circ}$. For which of the following values of $\mu$ can the ray undergo total internal reflection?
A point object is placed at a distance of 60 cm from a convex lens of focal length 30 cm. If a plane mirror were put perpendicular to the principal axis of the lens and at a distance of 40 cm from it, the final image would be formed at a distance of:
An object is mounted on a wall. Its image of equal size is to be obtained on a parallel wall with the help of a convex lens placed between these walls. The lens is kept at distance x in front of the second wall. The required focal length of the lens will be:
In the combination of the following gates, the output Y can be written in terms of inputs A and B as:
A beam of light is incident vertically on a glass slab of thickness 1 cm, and refractive index 1.5. A fraction A is reflected from the front surface while another fraction B enters the slab and emerges after reflection from the back surface. The time delay between them is:
For the logic circuit shown, the truth table is:
A p-n photodiode is made of a material with a band gap of $2.0\text{ eV}$. The minimum frequency of the radiation that can be absorbed by the material is nearly:
C and Si both have the same lattice structure, having 4 bonding electrons in each. However, C is an insulator whereas Si is an intrinsic semiconductor. This is because:
An oil drop of 12 excess electrons is held stationary under a constant electric field of $2.55 \times 10^4$ N/C. The density of the oil is $1.26 \text{ g/cm}^3$. The radius of the drop is: