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Errors in Measurements

137 Questions Start Allen Test
All Exams Allen Advance Errorless
Q51 Allen Error Analysis in Experiments MCQ
Two resistance are measured in ohm and is given as: $R_{1} = 3\Omega \pm 1\% ; R_{2} = 6\Omega \pm 2\%$ When they are connected in parallel, the percentage error in equivalent resistance is
A.
$3\%$
B.
$4.5\%$
C.
$0.67\%$
D.
$1.33\%$
Q52 Allen Error Analysis in Experiments MCQ
In a resonance-column experiment, the tuning fork is held above the open end of the glass tube. This can be done in two ways position (1) one prong below the other, and position (2) the two prongs at the same horizontal level. The correct position is ā€“
A.
(1) in all cases
B.
(2) in all cases
C.
(1) for first resonance and (2) for second resonance
D.
(2) for first resonance and (1) for second resonance
Q53 Allen Error Analysis in Experiments MCQ
A student is performing the experiment of Resonance Column. The diameter of the column tube is 4 cm. The distance frequency of the tuning fork is 512 Hz. The air temperature is $38^{\circ}$ C in which the speed of sound is 336 m/s. The zero of the meter scale coincides with the top end of the Resonance column. When first resonance occurs, the reading of the water level in the column is
A.
14.0
B.
15.2
C.
16.4
D.
17.6
Q54 Allen Error Analysis in Experiments MCQ
Following observation are taken from a travelling microscope to determine the refractive index of a liquid. Reading for the bottom of an empty beaker = 12.324 cm. Reading for the bottom of the beaker when partially filled with the liquid = 12.802 cm. Reading for the liquid surface = 13.895 cm. What is the refractive index of the liquid?
A.
1.232
B.
1.389
C.
1.437
D.
1.208
Q55 Allen Error Analysis in Experiments MCQ
An experiment with convex lens gives certain result which is represented by a student in the shown graph. What would be the power of the lens used.
A.
0.2D
B.
1D
C.
0.1D
D.
20D
Q56 Allen Error Analysis in Experiments MCQ
In an optics experiment, with the position of the object fixed, a student varies the position of the convex lens and for each position, the screen is adjusted to get a clear image of the object. A graph between the object distance u and the image distance v, from the lens, is plotted using the same scale for the two axes. A straight line passing through the origin and making an angle of $45^{\circ}$ with the x-axis meets the experimental curve at P. The coordinates of P will be:
A.
$\left(\frac{f}{2}, \frac{f}{2}\right)$
B.
$(f, f)$
C.
$(4f, 4f)$
D.
$(2f, 2f)$
Q57 Allen Error Analysis in Experiments MCQ
In Searle's apparatus, when experimental wire is loaded and unloaded, the air bubble in spirit level gets shifted.
A.
towards reference wire while loading and towards experimental wire while unloading
B.
towards experimental wire while loading and towards reference wire while unloading
C.
towards experimental wire, both the times, during loading and unloading
D.
towards reference wire, both the times during loading and unloading
Q58 Allen Error Analysis in Experiments MCQ
A student performs an experiment to determine the Young's modulus of a wire, exactly 2 m long, by Searle's method. In a particular reading, the student measures the extension in the length of the wire to be 0.80 mm with an uncertainty of $\pm0.05$ mm at a load of exactly 1.0 kg. The student also measures the diameter of the wire to be 0.4 mm with an uncertainty of $\pm0.01$ mm. Take $g=9.8\ m/s^{2}$ (exact). The Young's modulus obtained from the reading is
A.
$(2.0 \pm 0.3) \times 10^{11}\ N/m^{2}$
B.
$(2.0 \pm 0.2) \times 10^{11}\ N/m^{2}$
C.
$(2.0 \pm 0.1) \times 10^{11}\ N/m^{2}$
D.
$(2.0 \pm 0.05) \times 10^{11}\ N/m^{2}$
Q59 Allen Error Analysis in Experiments MCQ
In a meter bridge circuit, the known resistance used in resistance box is $100 \Omega$ (without any error, and the unknown resistor is put in right arm). The null point is found to be 40 cm from left end. If mm scale is used in the meter bridge then resistance of the unknown resistor is:
A.
$150\Omega \pm \frac{3}{8}\Omega$
B.
$150\Omega \pm \frac{1}{8}\Omega$
C.
$150\Omega \pm \frac{5}{8}\Omega$
D.
$150\Omega \pm \frac{7}{16}\Omega$
Q60 Allen Semiconductor MCQ
The manifestation of band structure in solids is due to -
A.
Bohr's correspondence principle.
B.
Pauli's exclusion principle.
C.
Heisenberg's uncertainty principle.
D.
Boltzmann's law.
Q61 Allen Semiconductor MCQ
In a P-N junction diode not connected to any circuit -
A.
the potential in the same everywhere.
B.
the P-type side is at a higher potential then the N-type side.
C.
there is an electric field at the junction directed from the N-type side to the P-type side.
D.
there is an electric field at the junction directed from the P-type to the N-type side.
Q62 Allen Semiconductor MCQ
If the ratio of the concentration of electrons to that of holes in a semiconductor is $\frac{7}{5}$ and the ratio of currents is $\frac{7}{4}$ then what is the ratio of their drift velocities -
A.
$\frac{5}{4}$
B.
$\frac{4}{7}$
C.
$\frac{5}{6}$
D.
$\frac{4}{5}$
Q63 Allen Semiconductor MCQ
For extrinsic semiconductors; when doping level is increased;
A.
Fermi-level of p-type semiconductor will go upward, and Fermi-level of n-type semiconductors will go downward.
B.
Fermi-level of p-type semiconductors will go downward, and Fermi-level of n-type semiconductor will go upward.
C.
Fermi-level of both p-type and n-type semiconductors will go upward for $T > T_{F} K$ and downward for $T < T_{F} K$ , where $T_{F}$ is Fermi temperature.
D.
Fermi-level of p and n-type semiconductors will not be affected.
Q64 Allen Semiconductor MCQ
A semiconductor pn junction at thermal equilibrium has the space charge density $\rho(x)$ profile as shown in the figure. The figure that best depicts the variation of the electric field E with x is :-(W denotes the width of the depletion layer)
A.
B.
C.
D.
Q65 Allen Semiconductor MCQ
In the following circuits $PN$ -junction diodes $D_{1}, D_{2}$ and $D_{3}$ are ideal for the following potential of $A$ and $B$ , the correct increasing order of resistance between $A$ and $B$ will be - (i) $-10V, -5V,$ (ii) $-5V, -10V$ (iii) $-4V, -12V$
A.
(i) < (ii) < (iii)
B.
(iii) < (ii) < (i)
C.
(ii) = (iii) < (i)
D.
(i) = (iii) < (ii)
Q66 Allen Semiconductor MCQ
The circuit has two oppositely connected ideal diodes in parallel. What is the current flowing in the circuit?
A.
2.31 A
B.
$1.33A$
C.
$1.71A$
D.
2.00 A
Q67 Allen Semiconductor MCQ
In given figure when input voltage increases,
A.
the current through $R_{S}$ , $R_{L}$ and Zener increases.
B.
the current through $R_{S}$ increases, Zener increases but through $R_{L}$ remains constant.
C.
the current through $R_{S}$ increases, through Zener decreases, $R_{L}$ increases.
D.
the current through $R_{S}$ increases, through Zener remains constant but $R_{L}$ increases.
Q68 Allen Semiconductor MCQ
If in a p-n junction diode, a square input signal of 10V is applied as shown. Then the output signal across $R_{L}$ will be :-
A.
B.
C.
D.
Q69 Allen Semiconductor MCQ
Ge and Si diodes start conducting at 0.3V and 0.7V respectively. In the following figure if Ge diode connection are reversed, the value of $V_{o}$ changes by: (Assume that the Ge diode has large breakdown voltage)
A.
$0.6V$
B.
0.8 V
C.
0.4 V
D.
$0.2V$
Q70 Allen Semiconductor MCQ
Figure shown a DC voltage regulator circuit, with a Zener diode of breakdown voltage = 6V. If the unregulated input voltage varies between 10 V to 16 V, then what is the maximum Zener current?
A.
2.5 mA
B.
3.5 mA
C.
7.5 mA
D.
1.5 mA
Q71 Allen Semiconductor MCQ
Take the breakdown voltage of the Zener diode used in the given circuit as 6V. For the input voltage shown in figure below, the time variation of the output voltage is : (Graphs drawn are schematic and not to scale)
A.
B.
C.
D.
Q72 Allen Semiconductor MCQ
Zener breakdown occurs in a p-n junction having p and n both:
A.
lightly doped and have wide depletion layer.
B.
heavily doped and have narrow depletion layer.
C.
lightly doped and have narrow depletion layer.
D.
heavily doped and have wide depletion layer.
Q73 Allen Semiconductor MCQ
Which of the following circuits correctly represents the following truth table? $\begin{array}{c c c} \text {A} & \text {B} & \text {C} \\ \hline 0 & 0 & 0 \\ 0 & 1 & 0 \\ 1 & 0 & 1 \\ 1 & 1 & 0 \end{array}$
A.
B.
C.
D.
Q74 Allen Semiconductor MCQ
For the given combination of gates, if the logic states of inputs A, B, C are as follows A = B = C = 0 and A = B = 1, C = 0 then the logic states of output D are -
A.
0, 0
B.
0, 1
C.
1, 0
D.
1,1
Q75 Allen Semiconductor MCQ
In the circuit below, A and B represent two inputs and C represents the output. The circuit represents.
A.
AND gate
B.
NAND gate
C.
OR gate
D.
NOR gate