Deck 25: Understanding Electrical Properties and Phenomena

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

Answer 1

20.8 × 10^-8 Ω m

Question 2

A filament lamp is

A)Ohmic
B)non-Ohmic
C)low resistive
D)non glowing

Answer 2

non-Ohmic

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

Answer 3

increases

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

Question 5

In semiconductors upon increasing temperature, conductivity

A)decreases
B)increases
C)remains constant
D)haphazard

Question 6

In NTC thermistor on increasing temperature, the resistance

A)increases
B)remains constant
C)decreases
D)behaves abruptly

Question 7

A component that allows unidirectional current to pass through it is

A)resistor
B)inductor
C)transformer
D)diode

Question 8

A rectifier converts

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

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

Question 10

Resistivity is measured in

A)ohms
B)ohm per meter
C)ohm meter
D)ohm sq. meter

Question 11

Component which obeys ohm's law is called

A)resistive component
B)efficient component
C)Ohmic component
D)non-Ohmic component

Question 12

At constant temperature, resistance and cross-sectional area are

A)directly related
B)not related
C)remains constant
D)inversely related

Question 13

Current and voltage are

A)directly related
B)inversely related
C)not related
D)gives abnormal behavior on graph

Question 14

At threshold voltage, resistance of diode

A)decreases
B)increases
C)remains constant
D)varies depending on the direction of voltage

Question 15

Resistance of a particular wire depends upon

A)size and shape
B)shape and length only
C)size only
D)shape only

Question 16

Resistance of metal is affected by

A)presence of impurities
B)temperature
C)both A and B
D)pressure

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

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

Question 19

Visible light has wavelength of

A)5 × 10-7 m
B)3 × 108 m
C)6 × 103 m
D)4 × 104 m

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

Question 21

For destructive interference, the path difference is

A)odd number of half wavelengths
B)even number of half wavelengths
C)whole number of wavelengths
D)even whole number of wavelengths

Question 22

Constructive interference happens when two waves are

A)out of phase
B)zero amplitude
C)in phase
D)in front

Question 23

Two waves with phase difference 180° have resultant of amplitude

A)one
B)zero
C)same as the single wave
D)doubles the single wave

Question 24

If two waves are in phase and have same amplitude then resultant wave has

A)half of amplitude of single wave
B)same amplitude as single wave
C)twice of amplitude of single wave
D)thrice of amplitude of single wave

Question 25

For listening radio in cars, external radio aerials are used because

A)radio waves have shorter wavelength
B)radio waves have longer wavelength
C)radio waves cannot pass through window
D)radio waves require a medium to propagate