Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics movement of the earth properties of stars life cycle of stars solar system and its planets types of galaxies galaxies

Sunspots on the photosphere are due to.

  1. Eclipses caused by planets

  2. Comparatively cooler regions

  3. Granulation's

  4. Cloudy weather on the earth
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sunspots are temporary phenomenon on the sun photosphere that appears as spots darker than the surrounding area.

They are regions of reduced surface temperature. 
Answer is $B$

Multiple choice physics electric current through conductors carbon resistance and colour codes for carbon resistance carbon resistors and their colour coding resistors

Which resistor is difficult to make of having a value less than about 2 Ohms? 

  1. Iron Resistor

  2. Carbon Resistor

  3. Wire wound Resistor

  4. Both b and c
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Carbon resistor is difficult to make of having a value less than about $20 $Ohms because they have ability to withstand high energy pulses, when current flow through the carbon composition body conducts the energy . So carbon resistor can be made with a higher resistance 

Multiple choice physics electric current through conductors carbon resistance and colour codes for carbon resistance carbon resistors and their colour coding resistors

Resistors are generally colour coded to:

  1. Indicate the type of the circuit in which they are to be used

  2. Identify whether they are ohmic or non-ohmic

  3. Determine their values in ohm

  4. Determine whether they are wire wound or composition resistors
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Components and wires are coded with colors to identify their value and function. The colors brown, red, green, blue, and violet are used as tolerance codes on 5-band resistors only.

So,Resistors are generally colour coded to determine their values in ohm.
Therefore, C is correct option.

Multiple choice physics electric current through conductors carbon resistance and colour codes for carbon resistance carbon resistors and their colour coding resistors

Which of the following is not true for wire wound resistor?

  1. It has a lower order of stability and reliability.

  2. It has high power rating with a low tolerance value.

  3. Easy to make wire wound resistor of value 0.01 Ohm.

  4. It is not suitable for high-frequency circuits.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A wire wound resistor is an electrical passive component that limits current. The resistive element exists out of an insulated metallic wire that is winded around a core of non-conductive material. The wire material has a high resistivity, and is usually made of an alloy such as Nickel-chromium (Nichrome) or a copper-nickel-manganese alloy called Manganin. Common core materials include ceramic, plastic and glass. 
It has a lower order of stability and reliability  is not true for wire wound resistor
Multiple choice physics electric current through conductors carbon resistance and colour codes for carbon resistance carbon resistors and their colour coding resistors

A given resistor has the following colour scheme of the various strips on it : Brown, black, green and silver. Its value in ohm is :

  1. $1.0 \times 10^4 \pm 10\%$

  2. $1.0 \times 10^5 \pm 10\%$

  3. $1.0 \times 10^6 \pm 10\%$

  4. $1.0 \times 10^7 \pm 10\%$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Numbers attached for brown, black, green and silver are $1, 0, 5, \pm10\%$. Therefore the resistance of given resistor
$= 10 \times 10^5\  \Omega  \pm 10\%$.

Multiple choice physics electric current through conductors carbon resistance and colour codes for carbon resistance carbon resistors and their colour coding resistors

Which of the following is not the disadvantage of wire wound resistor?

  1. It has a big size which is not suitable for many of the applications.

  2. It has high power rating with a low tolerance value.

  3. Resistance value gets changed by a change in temperature, humidity etc.

  4. It is not suitable for high-frequency circuits.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In wired resistors are mainly produced with alloys, since pure metal has a high temperature co-efficient.

Due to alloy temperature co-efficient of wire wound resistor is very low.
Therefore it is very less effected by temperature change.

Multiple choice physics electric current through conductors carbon resistance and colour codes for carbon resistance carbon resistors and their colour coding resistors

There are three red colored bands on a carbon resistor. What is its resistance ?

  1. $2.2$

  2. $2200$

  3. $\left( 2200\pm 20\% \right) $

  4. $1.76$ to $2.64$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

According to the color code of resistance,

code of red $=2$
code of red $=2$
code of red $=2$
The resistance of carbon resistor, $22\times 10^2 \pm20$%
$2200\pm20$%
The correct option is C.

Multiple choice physics electric current through conductors carbon resistance and colour codes for carbon resistance carbon resistors and their colour coding resistors

Carbon resistors are of two types :

  1. composition type resistor and film type resistor

  2. rheostat and film type resistor

  3. rheostat and variable resistor

  4. composition type resistor and rheostat
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Carbon resistors are of two types  composition type resistor and film type resistor.

There are a number of different types of fixed resistor:

Carbon composition: These types were once very common, but are now seldom used. 

Carbon film: This resistor type is formed by "cracking" a hydrocarbon onto a ceramic former.