Question 1

Resistivity of lead is {{}} A)22.5 × 10^-8 Ω m B)20.8 × 10^-8 Ω m C)10 Ω m D)5 Ω m

Accepted Answer

The resistivity of lead is 20.8 × 10^-8 Ω m, making option B the correct choice. Resistivity values are specific to materials and are typically found in tables or references for electrical properties.

Question 2

A filament lamp is
A)Ohmic
B)non-Ohmic
C)low resistive
D)non glowing

Accepted Answer

A filament lamp is non-Ohmic because its resistance changes with temperature, which varies as the current through the lamp changes.

Question 3

In case of filament lamp at higher voltages, the resistance of lamp
A)decreases
B)increases
C)remains constant
D)varies depending on the filament

Accepted Answer

The resistance of a filament lamp increases at higher voltages because as the filament gets hotter, its resistivity increases. This is due to the increase in temperature causing the atoms in the filament to vibrate more, making it harder for electrons to pass through, thus increasing resistance.

Question 4

If the connections across the resistor are reversed, then graph between current and potential difference is
A)variable
B)straight lined
C)constant
D)inverted

Accepted Answer

The graph between current and potential difference across a resistor remains a straight line according to Ohm's law (V = IR), regardless of the direction of connections, as it does not affect the resistor's behavior.

Question 5

In semiconductors upon increasing temperature, conductivity
A)decreases
B)increases
C)remains constant
D)haphazard

Accepted Answer

In semiconductors, increasing temperature leads to more charge carriers (electrons and holes) being generated, thus increasing conductivity.

Question 6

In NTC thermistor on increasing temperature, the resistance
A)increases
B)remains constant
C)decreases
D)behaves abruptly

Accepted Answer

NTC (Negative Temperature Coefficient) thermistors decrease in resistance as the temperature increases.

Question 7

A component that allows unidirectional current to pass through it is
A)resistor
B)inductor
C)transformer
D)diode

Accepted Answer

Diodes are semiconductor devices that allow current to flow in one direction only, making them ideal for rectification and other applications where unidirectional current flow is required.

Question 8

A rectifier converts
A)DC to AC
B)AC to DC
C)voltage in to current
D)current in to voltage

Accepted Answer

A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction.

Question 9

Threshold voltage at which LED emits light is
A)less than 0.6
B)equal to 0.6
C)more than 0.6
D)more than 3

Accepted Answer

The answer of Threshold voltage at which LED emits light...

Question 10

Resistivity is measured in
A)ohms
B)ohm per meter
C)ohm meter
D)ohm sq. meter

Accepted Answer

Resistivity, a material property, is measured in ohm meters (Ω·m). It quantifies how strongly a material opposes the flow of electric current.

Question 11

Component which obeys ohm's law is called
A)resistive component
B)efficient component
C)Ohmic component
D)non-Ohmic component

Accepted Answer

Ohmic components are those that obey Ohm's Law, meaning their current-voltage (I-V) relationship is linear, and the resistance remains constant regardless of the applied voltage.

Question 12

At constant temperature, resistance and cross-sectional area are
A)directly related
B)not related
C)remains constant
D)inversely related

Accepted Answer

Resistance and cross-sectional area are inversely related because resistance decreases as the cross-sectional area increases, given that resistivity and length are constant.

Question 13

Current and voltage are
A)directly related
B)inversely related
C)not related
D)gives abnormal behavior on graph

Accepted Answer

Current and voltage are directly related according to Ohm's Law, which states that the current through a conductor between two points is directly proportional to the voltage across the two points.

Question 14

At threshold voltage, resistance of diode
A)decreases
B)increases
C)remains constant
D)varies depending on the direction of voltage

Accepted Answer

At the threshold voltage, the resistance of a diode decreases as it starts to conduct electricity more efficiently.

Question 15

Resistance of a particular wire depends upon
A)size and shape
B)shape and length only
C)size only
D)shape only

Accepted Answer

The resistance of a wire depends on its size (length and cross-sectional area) and shape, as these factors determine how easily current can flow through the wire. The longer the wire or the smaller its cross-sectional area, the higher its resistance.

Question 16

Resistance of metal is affected by
A)presence of impurities
B)temperature
C)both A and B
D)pressure

Accepted Answer

Resistance of metal is affected by both the presence of impurities and temperature. Impurities can disrupt the uniformity of the metal's atomic structure, affecting electron flow, while temperature changes can cause the metal's atoms to vibrate more, making it harder for electrons to pass through.

Question 17

If current and potential difference are directly related then object follows
A)Ohm's law
B)Faraday's law
C)Ampere's law
D)Kirchhoff's law

Accepted Answer

Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points, assuming the temperature remains constant. This relationship is expressed as V = IR, where V is the voltage, I is the current, and R is the resistance.

Question 18

Effect of diffraction is greatest if waves pass through a gap with width equal to
A)frequency
B)wavelength
C)amplitude
D)wavefront

Accepted Answer

The effect of diffraction is greatest when waves pass through a gap or an opening that is approximately the same size as their wavelength. This is because when the size of the opening is comparable to the wavelength, the wave spreads out more significantly after passing through the gap.

Question 19

Visible light has wavelength of
A)5 × 10-7 m
B)3 × 108 m
C)6 × 103 m
D)4 × 104 m

Accepted Answer

Visible light has wavelengths in the range of approximately 400 to 700 nanometers (nm), and 5 × 10^-7 meters (or 500 nm) falls within this range, making it a correct representation of a wavelength of visible light.

Question 20

From double-slit experiment, the quantities to be measured are
A)slit separation
B)fringe separation
C)slit-to-screen distance
D)all of above

Accepted Answer

In the double-slit experiment, all three quantities: slit separation, fringe separation, and slit-to-screen distance are crucial for analyzing and understanding the interference pattern produced by the experiment. These measurements are used to calculate the wavelength of light or other particles used in the experiment.

Quiz 25: Understanding Electrical Properties and Phenomena

Resistivity of lead is {{}}

A filament lamp is

In case of filament lamp at higher voltages, the resistance of lamp

If the connections across the resistor are reversed, then graph between current and potential difference is

In semiconductors upon increasing temperature, conductivity

In NTC thermistor on increasing temperature, the resistance

A component that allows unidirectional current to pass through it is

A rectifier converts

Threshold voltage at which LED emits light is

Resistivity is measured in

Component which obeys ohm's law is called

At constant temperature, resistance and cross-sectional area are

Current and voltage are

At threshold voltage, resistance of diode

Resistance of a particular wire depends upon

Resistance of metal is affected by

If current and potential difference are directly related then object follows

Effect of diffraction is greatest if waves pass through a gap with width equal to

Visible light has wavelength of

From double-slit experiment, the quantities to be measured are