The junction diode in the following circuit requires a minimum current of 1 mA to be above the knee point (0.7 V) of its I-V characteristic curve. The voltage across the diode is independent of current above the knee point. If V_B = 5 V, then the maximum value of R so that the voltage is above the knee point, will be

In semiconductor the concentrations of electrons and holes are 8 ×10¹⁸/m³ and 5 × 10¹⁸/m respectively. If the mobilities of electrons and hole are 2.3 m²/volt-sec and 0.01 m²/volt-sec respectively, then semiconductor is

In the following common emitter configuration, an NPN transistor with current gain is used. The output voltage of the amplifier will be

The period of f(x) = [sin 5x] + |cos 6x| is -

The diode used in the circuit shown in the figure has a constant voltage drop of 0.5 V at all currents and a maximum power rating of 100 milliwatts. What should be the value of the resistor R, connected in series with the diode for obtaining maximum current

Current in the circuit will be

In the circuit, if the forward voltage drop for the diode is 0.5V, the current will be

A 2V battery is connected across the points A and B as shown in the figure given below. Assuming that the resistance of each diode is zero in forward bias and infinity in reverse bias, the current supplied by the battery when its positive terminal is connected to A is

In the figure, ABC; is triangle in which C = 90º and AB = 5 cm. D is a point on AB such that AD = 3 cm and = 60º. Then the length of AC is –

the m-n theorem states that 
 (m + n) cot θ = m cot α – n cot ß
this gives us the cotangent of the angle CDA which is further used in the sine rule to find the length of AC

If f(x) =, then equals

The figure shows four wire loops, with edge lengths of either L or 2L. All four loops will move through a region of uniform magnetic field (directed out of the page) at the same constant velocity. Rank the four loops according to the maximum magnitude of the e.m.f. induced as they move through the field, greatest first

A magnet is made to oscillate with a particular frequency, passing through a coil as shown in figure. The time variation of the magnitude of e.m.f. generated across the coil during one cycle is

A square loop of side 5 cm enters a magnetic field with 1 cms^-1. The front edge enters the magnetic field at t = 0 then which graph best depicts emf

Switch S of the circuit shown in figure. is closed at t = 0. If e denotes the induced

emf in L and i, the current flowing through the circuit at time t, which of the following graphs is correct

The current i in an induction coil varies with time t according to the graph shown

in figure. Which of the following graphs shows the induced emf (e) in the coil with time

A flexible wire bent in the form of a circle is placed in a uniform magnetic field perpendicular to the plane of the coil. The radius of the coil changes as shown in figure. The graph of induced emf in the coil is represented by