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A thin prism of angle $15^{\circ}$ made of glass of refractive index $\mu_1=1.5$ is combined with another prism of glass of refractive index $\mu_2=1.75$. The combination of the prism produces dispersion without deviation. The angle of the second prism should be:
Two thin lenses are of the same focal lengths (f), but one is convex and the other one is concave. When they are placed in contact with each other, the equivalent focal length of the combination will be:
A lens is made up of 3 different transparent media as shown in the figure. A point object O is placed on its axis beyond 2f. How many real images will be obtained on the other side?
A Zener diode, having breakdown voltage equal to $15\text{ V}$, is used in a voltage regulator circuit, as shown in the figure. The current through the diode is:
The device that can act as a complete electronic circuit is:
A p-n photodiode is fabricated from a semiconductor with a band gap of $2.5\text{ eV}$. It can detect a signal of wavelength:
The electron concentration in an n-type semiconductor is the same as the hole concentration in a p-type semiconductor. An external field (electric) is applied across each of them. Compare the currents in them.
The voltage gain of an amplifier with $9\%$ negative feedback is $10$. The voltage gain without feedback will be:
Sodium has body-centered packing. The distance between the two nearest atoms is $3.7\text{ \AA}$. The lattice parameter is:
In half-wave rectification, if the input frequency is $60\text{ Hz}$, the output frequency will be:
The circuit is equivalent to:
The collector current in a common base amplifier using n-p-n transistor is $24\text{ mA}$. If $80\%$ of the electrons released by the emitter are accepted by the collector, then the base current is numerically:
What is the output Y in the following circuit, when all the three inputs A, B, and C are first 0 and then 1?
Given below are two statements: Statement I: Photovoltaic devices can convert optical radiation into electricity. Statement II: The Zener diode is designed to operate under reverse bias in the breakdown.
The dimensions of emf in MKS are:
The above figure shows the circuit symbol of a transistor. Select the correct statements given below: (A) The transistor has two segments of p-type semiconductor separated by a segment of n-type semiconductor. (B) The emitter is of moderate size and heavily doped. (C) The central segment is thin and lightly doped. (D) The emitter base junction is reverse biased in common emitter amplifier circuit.
In a common emitter (CE) amplifier having a voltage gain G, the transistor used has transconductance $0.03 \text{ mho}$ and current gain 25. If the above transistor is replaced with another one with transconductance of $0.02 \text{ mho}$ and current gain of 20, the voltage gain will be:
The output (X) of the logic circuit shown in the figure will be:
In an n-type semiconductor, which of the following statement is true?
Transfer characteristics [output voltage ($V_o$) vs input voltage ($V_i$)] for a base biased transistor in CE configurations are as shown in the figure. For using the transistor as a switch, it is used: