Why the spring is made up of steel in comparison of copper

Copper is more costly than steel

Copper is more elastic than steel

Steel is more elastic than copper

A weight of 200 kg is suspended by vertical wire of length 600.5 cm. The area of cross-section of wire is \[1\,m{{m}^{2}}\]. When the load is removed, the wire contracts by 0.5 cm. The Young's modulus of the material of wire will be

\[1.35\times {{10}^{10}}\,N/{{m}^{2}}\]

\[2.35\times {{10}^{12}}\,N/{{m}^{2}}\]

\[1.35\times {{10}^{10}}\,N/{{m}^{2}}\]

\[13.5\times {{10}^{11}}\,N/{{m}^{2}}\]

\[23.5\times {{10}^{9}}\,N/{{m}^{2}}\]

The length of a wire is 1.0 m and the area of cross-section is \[1.0\times {{10}^{-2}}\,c{{m}^{2}}\]. If the work done for increase in length by 0.2 cm is 0.4 joule, then Young's modulus of the material of the wire is

\[2\times {{10}^{10}}\,N/{{m}^{2}}\]

\[2.0\times {{10}^{10}}\,N/{{m}^{2}}\]

\[4\times {{10}^{10}}\,N/{{m}^{2}}\]

\[2.0\times {{10}^{11}}\,N/{{m}^{2}}\]

\[2\times {{10}^{10}}\,N/{{m}^{2}}\]

Liquids have no Poisson's ratio, because

It has lesser density than solid

The elasticity of invar

Increases with temperature rise

Decreases with temperature rise

A steel ring of radius r and cross-section area ?A? is fitted on to a wooden disc of radius \[R(R>r)\]. If Young's modulus be E, then the force with which the steel ring is expanded is [EAMCET 1986]

\[\frac{E}{A}\left( \frac{R-r}{A} \right)\]

\[AE\left( \frac{R-r}{r} \right)\]

\[\frac{E}{A}\left( \frac{R-r}{A} \right)\]

An iron rod of length 2m and cross section area of \[50\,m{{m}^{2}}\], stretched by 0.5 mm, when a mass of 250 kg is hung from its lower end. Young's modulus of the iron rod is [AFMC 1999]

\[19.6\times {{10}^{15}}\,N/{{m}^{2}}\]

\[19.6\times {{10}^{10}}\,N/{{m}^{2}}\]

\[19.6\times {{10}^{15}}\,N/{{m}^{2}}\]

\[19.6\times {{10}^{18}}\,N/{{m}^{2}}\]

\[19.6\times {{10}^{20}}\,N/{{m}^{2}}\]

The relation between \[\gamma ,\,\eta \] and K for a elastic material is

\[\frac{1}{\eta }=\frac{1}{3\gamma }+\frac{1}{9K}\]

\[\frac{1}{K}=\frac{1}{3\gamma }+\frac{1}{9\eta }\]

\[\frac{1}{\gamma }=\frac{1}{3K}+\frac{1}{9\eta }\]

\[\frac{1}{\gamma }=\frac{1}{3\eta }+\frac{1}{9K}\]

The adiabatic elasticity of a gas is equal to\[\] [CPMT 1982]

\[\gamma \times \]specific heat

Peltier coefficient for the junction of a pair of metals is proportional to [MP PMT 1993; MP PET 1997]

Square of absolute temperature of the junction

T absolute temperature of the junction

Square of absolute temperature of the junction

\[\frac{1}{\text{Absolute temperature of the junction}}\]

\[\frac{1}{\text{Square of absolute temperature of the junction}}\]

As the temperature of hot junction of a thermo‑couple is increased (while cold junction is at constant temperature), the thermo e.m.f.

In minimum at neutral temperature

Increases uniformly at constant rate

Increases slowly in the beginning and more rapidly at higher temperatures

Increases more rapidly in the beginning but less rapidly at higher temperatures

In minimum at neutral temperature

When current is passed in antimony-bismuth couple, then

The junction becomes hot when the current is from bismuth to antimony

The junction becomes hot when current flows from antimony to bismuth

Forty electric bulbs are connected in series across a 220 V supply. After one bulb is fused the remaining 39 are connected again in series across the same supply. The illumination will be

more with 40 bulbs than with 39

more with 39 bulbs than with 40

in the ratio \[{{40}^{2}}:{{39}^{2}}\]

Assertion : The resistivity of a semiconductor increases with temperature. Reason : The atoms of a semiconductor vibrate with larger amplitude at higher temperatures thereby increasing its resistivity [AIIMS 2003]

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

12583 + Mcqs in Physics in Joint Entrance Exam - Main (JEE Main) Page 250 McqOptions

12451.	The area of cross section of a steel wire \[(Y=2.0\times {{10}^{11}}N/{{m}^{2}})\]is \[0.1\ c{{m}^{2}}\]. The force required to double its length will be [MP PET 2002]
A.	\[2\times {{10}^{12}}N\]
B.	\[2\times {{10}^{11}}N\]
C.	\[2\times {{10}^{10}}N\]
D.	\[2\times {{10}^{6}}N\]
Answer» E.

Discussion

12452.	There is no change in the volume of a wire due to change in its length on stretching. The Poisson's ratio of the material of the wire is [MH CET 2004]
A.	0.5
B.	? 0.50
C.	0.25
D.	? 0.25
Answer» C. 0.25

Discussion

12453.	According to Hook?s law force is proportional to [RPET 2003]
A.	\[\frac{1}{x}\]
B.	\[\frac{1}{{{x}^{2}}}\]
C.	x
D.	\[{{x}^{2}}\]
Answer» D. \[{{x}^{2}}\]

Discussion

12454.	The material which practically does not show elastic after effect is [JIPMER 1997; AMU (Engg.) 1999]
A.	Copper
B.	Rubber
C.	Steel
D.	Quartz
Answer» E.

Discussion

12455.	A and B are two wires. The radius of A is twice that of B. They are stretched by the some load. Then the stress on B is [MP PMT 1993]
A.	Equal to that on A
B.	Four times that on A
C.	Two times that on A
D.	Half that on A
Answer» C. Two times that on A

Discussion

12456.	The increase in length is l of a wire of length L by the longitudinal stress. Then the stress is proportional to [MP PET 1986]
A.	L/l
B.	l/L
C.	\[l\times L\]
D.	\[{{l}^{2}}\times L\]
Answer» C. \[l\times L\]

Discussion

12457.	If x longitudinal strain is produced in a wire of Young's modulus y, then energy stored in the material of the wire per unit volume is [MP PMT 1987, 89, 92; CPMT 1997; Pb. PMT 1999; KCET 2000; AIIMS 2001]
A.	\[y{{x}^{2}}\]
B.	\[2\,y{{x}^{2}}\]
C.	\[\frac{1}{2}{{y}^{2}}x\]
D.	\[\frac{1}{2}y{{x}^{2}}\]
Answer» E.

Discussion

12458.	Why the spring is made up of steel in comparison of copper
A.	Copper is more costly than steel
B.	Copper is more elastic than steel
C.	Steel is more elastic than copper
D.	None of the above
Answer» D. None of the above

Discussion

12459.	A weight of 200 kg is suspended by vertical wire of length 600.5 cm. The area of cross-section of wire is \[1\,m{{m}^{2}}\]. When the load is removed, the wire contracts by 0.5 cm. The Young's modulus of the material of wire will be
A.	\[2.35\times {{10}^{12}}\,N/{{m}^{2}}\]
B.	\[1.35\times {{10}^{10}}\,N/{{m}^{2}}\]
C.	\[13.5\times {{10}^{11}}\,N/{{m}^{2}}\]
D.	\[23.5\times {{10}^{9}}\,N/{{m}^{2}}\]
Answer» B. \[1.35\times {{10}^{10}}\,N/{{m}^{2}}\]

Discussion

12460.	The length of a wire is 1.0 m and the area of cross-section is \[1.0\times {{10}^{-2}}\,c{{m}^{2}}\]. If the work done for increase in length by 0.2 cm is 0.4 joule, then Young's modulus of the material of the wire is
A.	\[2.0\times {{10}^{10}}\,N/{{m}^{2}}\]
B.	\[4\times {{10}^{10}}\,N/{{m}^{2}}\]
C.	\[2.0\times {{10}^{11}}\,N/{{m}^{2}}\]
D.	\[2\times {{10}^{10}}\,N/{{m}^{2}}\]
Answer» D. \[2\times {{10}^{10}}\,N/{{m}^{2}}\]

Discussion

12461.	The ratio of diameters of two wires of same material is n : 1. The length of wires are 4 m each. On applying the same load, the increase in length of thin wire will be
A.	\[{{n}^{2}}\] times
B.	n times
C.	2n times
D.	None of the above
Answer» B. n times

Discussion

12462.	Liquids have no Poisson's ratio, because
A.	It has no definite shape
B.	It has greater volume
C.	It has lesser density than solid
D.	None of the above
Answer» B. It has greater volume

Discussion

12463.	The elasticity of invar
A.	Increases with temperature rise
B.	Decreases with temperature rise
C.	Does not depend on temperature
D.	None of the above
Answer» D. None of the above

Discussion

12464.	A steel ring of radius r and cross-section area ?A? is fitted on to a wooden disc of radius \[R(R>r)\]. If Young's modulus be E, then the force with which the steel ring is expanded is [EAMCET 1986]
A.	\[AE\frac{R}{r}\]
B.	\[AE\left( \frac{R-r}{r} \right)\]
C.	\[\frac{E}{A}\left( \frac{R-r}{A} \right)\]
D.	\[\frac{Er}{AR}\]
Answer» C. \[\frac{E}{A}\left( \frac{R-r}{A} \right)\]

Discussion

12465.	Two wires ?A? and ?B? of the same material have radii in the ratio 2 : 1 and lengths in the ratio 4 : 1. The ratio of the normal forces required to produce the same change in the lengths of these two wires is [Haryana CEE 1996]
A.	0.0423611111111111
B.	2 : 1
C.	1 : 4
D.	1 : 2
Answer» B. 2 : 1

Discussion

12466.	The possible value of Poisson's ratio is [EAMCET (Med.) 1995]
A.	1
B.	0.9
C.	0.8
D.	0.4
Answer» E.

Discussion

12467.	An iron rod of length 2m and cross section area of \[50\,m{{m}^{2}}\], stretched by 0.5 mm, when a mass of 250 kg is hung from its lower end. Young's modulus of the iron rod is [AFMC 1999]
A.	\[19.6\times {{10}^{10}}\,N/{{m}^{2}}\]
B.	\[19.6\times {{10}^{15}}\,N/{{m}^{2}}\]
C.	\[19.6\times {{10}^{18}}\,N/{{m}^{2}}\]
D.	\[19.6\times {{10}^{20}}\,N/{{m}^{2}}\]
Answer» B. \[19.6\times {{10}^{15}}\,N/{{m}^{2}}\]

Discussion

12468.	The relation between \[\gamma ,\,\eta \] and K for a elastic material is
A.	\[\frac{1}{\eta }=\frac{1}{3\gamma }+\frac{1}{9K}\]
B.	\[\frac{1}{K}=\frac{1}{3\gamma }+\frac{1}{9\eta }\]
C.	\[\frac{1}{\gamma }=\frac{1}{3K}+\frac{1}{9\eta }\]
D.	\[\frac{1}{\gamma }=\frac{1}{3\eta }+\frac{1}{9K}\]
Answer» E.

Discussion

12469.	The length of an elastic string is a metre when the longitudinal tension is 4 N and b metre when the longitudinal tension is 5 N. The length of the string in metre when the longitudinal tension is 9 N is [EAMCET 2001]
A.	\[a-b\]
B.	\[5b-4a\]
C.	\[2b-\frac{1}{4}a\]
D.	\[4a-3b\]
Answer» C. \[2b-\frac{1}{4}a\]

Discussion

12470.	Which statement is true for a metal [DPMT 2001]
A.	\[Y<\eta \]
B.	\[Y=\eta \]
C.	\[Y>\eta \]
D.	\[Y<1/\eta \]
Answer» D. \[Y<1/\eta \]

Discussion

12471.	Shearing stress causes change in [RPET 2002; BCECE 2001, 04]
A.	Length
B.	Breadth
C.	Shape
D.	Volume
Answer» D. Volume

Discussion

12472.	Modulus of rigidity of diamond is
A.	Too less
B.	Greater than all matters
C.	Less than all matters
D.	Zero
Answer» C. Less than all matters

Discussion

12473.	The adiabatic elasticity of a gas is equal to\[\] [CPMT 1982]
A.	\[\gamma \times \]density
B.	\[\gamma \times \]volume
C.	\[\gamma \times \]pressure
D.	\[\gamma \times \]specific heat
Answer» D. \[\gamma \times \]specific heat

Discussion

12474.	Peltier coefficient for the junction of a pair of metals is proportional to [MP PMT 1993; MP PET 1997]
A.	T absolute temperature of the junction
B.	Square of absolute temperature of the junction
C.	\[\frac{1}{\text{Absolute temperature of the junction}}\]
D.	\[\frac{1}{\text{Square of absolute temperature of the junction}}\]
Answer» B. Square of absolute temperature of the junction

Discussion

12475.	The smallest temperature difference that can be measured with a combination of a thermocouple of thermo e.m.f. 30mV per degree and a galvanometer of 50 ohm resistance, capable of measuring a minimum current of 3 ´ 10?7 amp is [MP PET 2000]
A.	0.5 degree
B.	1.0 degree
C.	1.5 degree
D.	2.0 degree
Answer» B. 1.0 degree

Discussion

12476.	The thermocouple is based on the principle of [MP PET 1984; AFMC 1998; BCECE 2003]
A.	Seebeck effect
B.	Thomson effect
C.	Peltier effect
D.	Joule effect
Answer» B. Thomson effect

Discussion

12477.	As the temperature of hot junction of a thermo‑couple is increased (while cold junction is at constant temperature), the thermo e.m.f.
A.	Increases uniformly at constant rate
B.	Increases slowly in the beginning and more rapidly at higher temperatures
C.	Increases more rapidly in the beginning but less rapidly at higher temperatures
D.	In minimum at neutral temperature
Answer» D. In minimum at neutral temperature

Discussion

12478.	In a thermocouple, the temperature that does not depend on the temperature of the cold junction is called
A.	Neutral temperature
B.	Temperature of inversion
C.	Both the above
D.	None of the above
Answer» B. Temperature of inversion

Discussion

12479.	When current is passed in antimony-bismuth couple, then
A.	The junction becomes hot when the current is from bismuth to antimony
B.	The junction becomes hot when current flows from antimony to bismuth
C.	Both junctions become hot
D.	Both junctions become cold
Answer» C. Both junctions become hot

Discussion

12480.	A potential difference of 220 V is maintained across a 12000 ohm rheostat, as shown in the figure. The voltmeter has a resistance of 6000 ohm and point c is at one-fourth of the distance from a to b, Therefore, the reading of the voltmeter will be
A.	32 V
B.	36 V
C.	40 V
D.	42 V
Answer» D. 42 V

Discussion

12481.	125 cm of potentiometer wire balances the emf of a cell and 100 cm of the wire is required for balance, if the poles of the cell are joined by \[2\Omega \]resistor. Then the internal resistance of the cell is
A.	\[0.25\Omega \]
B.	\[0.5\Omega \]
C.	\[0.75\Omega \]
D.	\[1.25\Omega \]
Answer» C. \[0.75\Omega \]

Discussion

12482.	Two cities are 150 km apart. Electric power is sent from one city to another city through copper wires. The fall of potential per km is 8 volt and the average resistance per km is \[0.5\Omega \]. The power loss in the wires is:
A.	19.2 W
B.	19.2 kW
C.	19.2 J
D.	12.2 kW
Answer» C. 19.2 J

Discussion

12483.	A wire of radius r and another wire of radius 2r, both of same material and length are connected in series to each other. The combination is connected across a battery. The ratio of the heats produced in the two wires will be
A.	4
B.	2
C.	0.5
D.	0.25
Answer» B. 2

Discussion

12484.	Forty electric bulbs are connected in series across a 220 V supply. After one bulb is fused the remaining 39 are connected again in series across the same supply. The illumination will be
A.	more with 40 bulbs than with 39
B.	more with 39 bulbs than with 40
C.	equal in both the cases
D.	in the ratio \[{{40}^{2}}:{{39}^{2}}\]
Answer» C. equal in both the cases

Discussion

12485.	The circuit shown here has two batteries of 8.0 V and 16.0 V and three resistors \[3\Omega \], \[9\Omega \,\] and \[9\Omega \,\] a capacitor of \[5.0\text{ }\mu F.\] How much is the current I in the circuit in steady state?
A.	1.6 A
B.	0.67 A
C.	2.5 A
D.	0.25 A
Answer» C. 2.5 A

Discussion

12486.	In the circuit shown in the figure, find the current in \[45\Omega \].
A.	0.166666666666667
B.	2.5 A
C.	0.0833333333333333
D.	None of these
Answer» D. None of these

Discussion

12487.	Determine the current in \[2\Omega \]resistor.
A.	0.0416666666666667
B.	1.5 A
C.	0.9 A
D.	0.6 A
Answer» D. 0.6 A

Discussion

12488.	A battery of emf 10V and internal resistance 30hm is connected to a resister. The current in the circuit is 0.5 amp. The terminal voltage of the battery when the circuit is closed is
A.	10V
B.	zero
C.	1.5V
D.	8.5V
Answer» E.

Discussion

12489.	In the given mesh, each resistor has resistance R. The effective resistance between the terminals A and B is
A.	\[\frac{3R}{8}\]
B.	\[\frac{R}{2}\]
C.	\[R\]
D.	\[2R\]
Answer» B. \[\frac{R}{2}\]

Discussion

12490.	A wire of resistance 12 ohms per meter is bent to form a square of total length 10 cm. The resistance between its two forthest points is
A.	\[1.2\Omega \]
B.	\[6\Omega \]
C.	\[1.5\Omega \]
D.	\[2.8\Omega \]
Answer» B. \[6\Omega \]

Discussion

12491.	In Fig. find the value of resistor to be connected between C and D, so that the resistance of the entire circuit between A and B does not change with the number of elementary seta.
A.	\[R\]
B.	\[R\left( \sqrt{3}-1 \right)\]
C.	\[3R\]
D.	\[R\left( \sqrt{3}+1 \right)\]
Answer» C. \[3R\]

Discussion

12492.	A wire has linear resistance \[\rho \](in Ohm/m). Find the resistance R between points A and B if the side of the larger square is 'd'.
A.	\[\rho d/\sqrt{2}\]
B.	\[\sqrt{2}\rho d\]
C.	\[2rd\]
D.	None of these
Answer» B. \[\sqrt{2}\rho d\]

Discussion

12493.	A straight conductor of uniform cross-section carries a current I. Ifs is the specific charge of an electron, the momentum of all the free electrons per unit length of the conductor, due to their drift velocity only is
A.	\[I\,s~\]
B.	\[\sqrt{I/s}\]
C.	\[I/s~~~\]
D.	\[{{\left( I/s \right)}^{2}}\]
Answer» D. \[{{\left( I/s \right)}^{2}}\]

Discussion

12494.	The length of a given cylindrical wire is increased by 100%. Due to the consequent decrease in diameter the change in the resistance of the wire will be
A.	2
B.	1
C.	0.5
D.	3
Answer» E.

Discussion

12495.	In the part of a circuit shown in figure, the potential difference \[({{V}_{G}}-{{V}_{H}})\]between points G and H will be
A.	0V
B.	15V
C.	7V
D.	3V
Answer» D. 3V

Discussion

12496.	Two conductors AB and CD are connected between two parallel resistors in such a way that no current flows through them. Then a wire is connected between E and F.
A.	There is no current in EF
B.	Current flows from E to F
C.	Current flows F to E
D.	None of these
Answer» C. Current flows F to E

Discussion

12497.	Assertion : The resistivity of a semiconductor increases with temperature. Reason : The atoms of a semiconductor vibrate with larger amplitude at higher temperatures thereby increasing its resistivity [AIIMS 2003]
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
Answer» E.

Discussion

12498.	Find out the value of current through 2W resistance for the given circuit [IIT-JEE (Screening) 2005]
A.	5 A
B.	2 A
C.	Zero
D.	4 A
Answer» D. 4 A

Discussion

12499.	The resistivity of iron is\[1\times {{10}^{-7}}\,ohm-m\]. The resistance of a iron wire of particular length and thickness is 1 ohm. If the length and the diameter of wire both are doubled, then the resistivity in \[ohm-m\] will be [CPMT 1983; DPMT 1999]
A.	\[1\times {{10}^{-7}}\]
B.	\[2\times {{10}^{-7}}\]
C.	\[4\times {{10}^{-7}}\]
D.	\[8\times {{10}^{-7}}\]
Answer» B. \[2\times {{10}^{-7}}\]

Discussion

12500.	Find the power of the circuit [AIEEE 2002]
A.	1.5 W
B.	2 W
C.	1 W
D.	None of these
Answer» D. None of these

Discussion

Explore topic-wise MCQs in Joint Entrance Exam - Main (JEE Main).

The area of cross section of a steel wire \[(Y=2.0\times {{10}^{11}}N/{{m}^{2}})\]is \[0.1\ c{{m}^{2}}\]. The force required to double its length will be [MP PET 2002]

There is no change in the volume of a wire due to change in its length on stretching. The Poisson's ratio of the material of the wire is [MH CET 2004]

According to Hook?s law force is proportional to [RPET 2003]

The material which practically does not show elastic after effect is [JIPMER 1997; AMU (Engg.) 1999]

A and B are two wires. The radius of A is twice that of B. They are stretched by the some load. Then the stress on B is [MP PMT 1993]

The increase in length is l of a wire of length L by the longitudinal stress. Then the stress is proportional to [MP PET 1986]

If x longitudinal strain is produced in a wire of Young's modulus y, then energy stored in the material of the wire per unit volume is [MP PMT 1987, 89, 92; CPMT 1997; Pb. PMT 1999; KCET 2000; AIIMS 2001]

Why the spring is made up of steel in comparison of copper

A weight of 200 kg is suspended by vertical wire of length 600.5 cm. The area of cross-section of wire is \[1\,m{{m}^{2}}\]. When the load is removed, the wire contracts by 0.5 cm. The Young's modulus of the material of wire will be

The length of a wire is 1.0 m and the area of cross-section is \[1.0\times {{10}^{-2}}\,c{{m}^{2}}\]. If the work done for increase in length by 0.2 cm is 0.4 joule, then Young's modulus of the material of the wire is

The ratio of diameters of two wires of same material is n : 1. The length of wires are 4 m each. On applying the same load, the increase in length of thin wire will be

Liquids have no Poisson's ratio, because

The elasticity of invar

A steel ring of radius r and cross-section area ?A? is fitted on to a wooden disc of radius \[R(R>r)\]. If Young's modulus be E, then the force with which the steel ring is expanded is [EAMCET 1986]

Two wires ?A? and ?B? of the same material have radii in the ratio 2 : 1 and lengths in the ratio 4 : 1. The ratio of the normal forces required to produce the same change in the lengths of these two wires is [Haryana CEE 1996]

The possible value of Poisson's ratio is [EAMCET (Med.) 1995]

An iron rod of length 2m and cross section area of \[50\,m{{m}^{2}}\], stretched by 0.5 mm, when a mass of 250 kg is hung from its lower end. Young's modulus of the iron rod is [AFMC 1999]

The relation between \[\gamma ,\,\eta \] and K for a elastic material is

The length of an elastic string is a metre when the longitudinal tension is 4 N and b metre when the longitudinal tension is 5 N. The length of the string in metre when the longitudinal tension is 9 N is [EAMCET 2001]

Which statement is true for a metal [DPMT 2001]

Shearing stress causes change in [RPET 2002; BCECE 2001, 04]

Modulus of rigidity of diamond is

The adiabatic elasticity of a gas is equal to\[\] [CPMT 1982]

Peltier coefficient for the junction of a pair of metals is proportional to [MP PMT 1993; MP PET 1997]

The smallest temperature difference that can be measured with a combination of a thermocouple of thermo e.m.f. 30mV per degree and a galvanometer of 50 ohm resistance, capable of measuring a minimum current of 3 ´ 10?7 amp is [MP PET 2000]

The thermocouple is based on the principle of [MP PET 1984; AFMC 1998; BCECE 2003]

As the temperature of hot junction of a thermo‑couple is increased (while cold junction is at constant temperature), the thermo e.m.f.

In a thermocouple, the temperature that does not depend on the temperature of the cold junction is called

When current is passed in antimony-bismuth couple, then

A potential difference of 220 V is maintained across a 12000 ohm rheostat, as shown in the figure. The voltmeter has a resistance of 6000 ohm and point c is at one-fourth of the distance from a to b, Therefore, the reading of the voltmeter will be

125 cm of potentiometer wire balances the emf of a cell and 100 cm of the wire is required for balance, if the poles of the cell are joined by \[2\Omega \]resistor. Then the internal resistance of the cell is

Two cities are 150 km apart. Electric power is sent from one city to another city through copper wires. The fall of potential per km is 8 volt and the average resistance per km is \[0.5\Omega \]. The power loss in the wires is:

A wire of radius r and another wire of radius 2r, both of same material and length are connected in series to each other. The combination is connected across a battery. The ratio of the heats produced in the two wires will be

Forty electric bulbs are connected in series across a 220 V supply. After one bulb is fused the remaining 39 are connected again in series across the same supply. The illumination will be

The circuit shown here has two batteries of 8.0 V and 16.0 V and three resistors \[3\Omega \], \[9\Omega \,\] and \[9\Omega \,\] a capacitor of \[5.0\text{ }\mu F.\] How much is the current I in the circuit in steady state?

In the circuit shown in the figure, find the current in \[45\Omega \].

Determine the current in \[2\Omega \]resistor.

A battery of emf 10V and internal resistance 30hm is connected to a resister. The current in the circuit is 0.5 amp. The terminal voltage of the battery when the circuit is closed is

In the given mesh, each resistor has resistance R. The effective resistance between the terminals A and B is

A wire of resistance 12 ohms per meter is bent to form a square of total length 10 cm. The resistance between its two forthest points is

In Fig. find the value of resistor to be connected between C and D, so that the resistance of the entire circuit between A and B does not change with the number of elementary seta.

A wire has linear resistance \[\rho \](in Ohm/m). Find the resistance R between points A and B if the side of the larger square is 'd'.

A straight conductor of uniform cross-section carries a current I. Ifs is the specific charge of an electron, the momentum of all the free electrons per unit length of the conductor, due to their drift velocity only is

The length of a given cylindrical wire is increased by 100%. Due to the consequent decrease in diameter the change in the resistance of the wire will be

In the part of a circuit shown in figure, the potential difference \[({{V}_{G}}-{{V}_{H}})\]between points G and H will be

Two conductors AB and CD are connected between two parallel resistors in such a way that no current flows through them. Then a wire is connected between E and F.

Assertion : The resistivity of a semiconductor increases with temperature. Reason : The atoms of a semiconductor vibrate with larger amplitude at higher temperatures thereby increasing its resistivity [AIIMS 2003]

Find out the value of current through 2W resistance for the given circuit [IIT-JEE (Screening) 2005]

The resistivity of iron is\[1\times {{10}^{-7}}\,ohm-m\]. The resistance of a iron wire of particular length and thickness is 1 ohm. If the length and the diameter of wire both are doubled, then the resistivity in \[ohm-m\] will be [CPMT 1983; DPMT 1999]

Find the power of the circuit [AIEEE 2002]