1 ) A wire of resistance R is cut into two equal parts . Then two parts are joined in parallel . What would be resistance ?
A ) R/2 , B ) R/4 ,
C ) 2R , D ) None of these ,
Correct Answer : - B ) R/4 ,
Solution : -
As we know that resistance is directly related to the length of a wire .
Ø R α L ,
Ø So , R/2 α L/2 ,
So resistance in parallel : -
Ø 1/Rp = 1/R1 + 1/R2 ,
Ø 1/Rp = 1/(R/2) + 1/(R/2) ,
Ø 1/Rp = 2/R + 2/R ,
Ø 1/Rp = 4/R ,
Ø Rp = R/4 , Answer .
2 ) Formula for viscosity : - È = F / rv .
3 ) Phase angle in SHM is used to specify ………… of the motion .
A ) displacement , B ) direction ,
C ) both , D ) None of these ,
Correct Answer : - C ) both ,
4 ) The number of loops in stationary waves depends on …………. of waves .
A ) velocity , B ) frequency ,
C ) wavelength , D ) None of these ,
Correct Answer : - B ) frequency ,
5 ) …………… will not changes , when light changes the medium eg . from rare to denser or vice versa .
A ) velocity , B ) wavelength ,
C ) frequency , D ) None of these ,
Correct Answer : - C ) frequency ,
6 ) The power of objective and eye piece of telescope is 0.5 diopter and 10 diopter respectively . Then magnifying power of telescope will be ?
A ) 0.05 , B ) 0.5 ,
C ) 5 , D ) None of these ,
Correct Answer : - A ) 0.05 ,
Solution : -
7 ) A wire of resistance R is cut into three equal parts . Then these three parts are joined in series . What would be resistance ?
A ) 1R , B ) 3R ,
C ) R/3 , D ) None of these ,
Correct Answer : - A ) 1R ,
Solution : -
So each wire will become R/3 .
So Rs = R1 + R2 + R3 ,
Rs = R/3 + R/3 + R/3 .
Rs = 3R/3 = R , Answer .
8 ) Two metallic conductors have the same value of resistivity . These conductors are differentiable by their …………….. ,
A ) resistance , B ) inductance ,
C ) conductance , D ) None of these ,
Correct Answer : - C ) conductance ,
9 ) If current flows in same direction , so wires will ………… each other .
A ) attract , B ) repel ,
C ) neither attract nor repel , D ) None of these ,
Correct Answer : - A ) attract ,
10 ) The strength of magnetic field around a solenoid can be increased by : -
A ) increasing the current ,
B ) increasing no. of turns ,
C ) placing an iron core inside the solenoid ,
D ) All of these ,
Correct Answer : - D ) All of these ,
11 ) The conversion of AC to DC is known as : -
A ) modulation , B ) rectification ,
C ) amplification , D ) None of these ,
Correct Answer : - B ) rectification ,
Now go to online quiz section and Physics Quiz 7 is uploaded related to these mcqs , so check your preparation by this link : -
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