Physics M.C.Q (1 Marks)

Assertion  : 29 is the equivalent decimal number of binary number 11101.

Reason      : (11101)₂ = (1 × 2⁴ + 1 × 2³ + 1 × 2² + 0 × 2¹ + 1 × 2⁰ )₁₀   = (16 + 8 + 4 + 0 + 1)₁₀ = (29)₁₀

The voltage gain of the following amplifier is

In the grid circuit of a triode a signal E = 2  is applied. If m = 14 and r_p =10 kW then root mean square current flowing through   will be

Which of the following figures correctly shows the phase relation between the input signal and the output signal of triode amplifier

The variation of anode current in a triode corresponding to a change in grid potential at three different values of the plate potential is shown in the diagram. The mutual conductance of the triode is

The plate current in a triode is given by    where I_p, V_p and V_g are the values of plate current, plate voltage and grid voltage, respectively. What are the triode parameters m, r_p and g_m for the operating point at   and  ?

In the following common emitter configuration an NPN transistor with current gain b = 100 is used. The output voltage of the amplifier will be

In the circuit shown in figure the maximum output voltage V₀ is

The value of plate current in the given circuit diagram will be

Which represents NAND gate

The truth table shown in figure is for

Given below are four logic gate symbol (figure). Those for OR, NOR and NAND are respectively

A semiconductor X is made by doping a germanium crystal with arsenic (Z = 33). A second semiconductor Y is made by doping germanium with indium (Z = 49). The two are joined end to end and connected to a battery as shown. Which of the following statements is correct

The combination of ‘NAND’ gates shown here under (figure) are equivalent to

For the given circuit of PN-junction diode, which of the following statement is correct

Which is reverse biased diode

In the case of forward biasing of PN-junction, which one of the following figures correctly depicts the direction of flow of carriers

(a)

(b)

(c)

(d)

Which one is in forward bias

P-type semiconductor is formed when

A. As impurity is mixed in Si                                                                         B. Al impurity is mixed in Si

C. B impurity is mixed in Ge                                                                         D. P impurity is mixed in Ge

Assertion   : The following circuit represents 'OR' gate

Reason     : For the above circuit Y =

In a common emitter transistor, the current gain is 80. What is the change in collector current, when the change in base current is 250 mA

This symbol represents

For a crystal system, a = b = c, a = b = g  ¹ 90^o, the system is

The symbol given in figure represents

The resistance of a germanium junction diode whose V - I  is shown in figure is  

(a) 5 kW

(b) 0.2 kW

(c) 2.3 kW

(d)

The mutual characteristic of triode is

(a)

(a)

(c)

(d)

Different voltages are applied across a P-N junction and the currents are measured for each value. Which of the following graphs is obtained between voltage and current

(a)

(b)

(c)

(d)

The curve between charge density and distance near P-N junction will be

(a)

(b)

(c)

(d)

For the diode, the characteristic curves are given at different temperature. The relation between the temperatures is

(a)

(b)

(c)

(d) None of the above

When a potential difference is applied across, the current passing through

The temperature (T) dependence of resistivity (r) of a semiconductor is represented by

(a)

(b)

(c)

(d)

The following truth table corresponds to the logic gate

The current through an ideal PN-junction shown in the following circuit diagram will be

Before the saturation state of a diode at the plate voltages of 400 V and 200 V respectively the currents are i₁ and i₂ respectively. The ratio i₁/i₂ will be

(a)

(b) 2

(c) 2

(d) 1/2

For a given plate-voltage, the plate current in a triode is maximum when the potential of

The relation between a and b parameters of current gains for a transistors is given by

(a) α =

(b) α =

(c) α =

(d) α =

For a transistor, in a common emitter arrangement, the alternating current gain b  is given by

(a) β =

(b) β =

(c) β =

(d) β =

Which of these is unipolar transistor

In a transistor configuration b-parameter is

(a)

(b)

(c)

(d)

In forward bias, the width of potential barrier in a P-N junction diode

The depletion layer in the P-N junction region is caused by

In P-N junction, avalanche current flows in circuit when biasing is

In the depletion region of an unbiased P-N junction diode there are

If the forward voltage in a semiconductor diode is doubled, the width of the depletion layer will

The electrical resistance of depletion layer is large because

The reverse biasing in a PN junction diode

PN-junction diode works as a insulator, if connected

The electrical circuit used to get smooth dc output from a rectifier circuit is called

The cut-in voltage for silicon diode is approximately

In a junction diode, the holes are due to