2492 + Interview Questions in CURRENT-ELECTRICITY IN GENERAL AWARENESS Page 48 InterviewSolution

2351.	Three resistances are connected to form a T-shape as shown in the figure. Then, the current in the `4Omega` resistor is A. `0.93A`B. `4.5A`C. `2.5A`D. `1.57A`
Answer» Correct Answer - B

Discussion

2352.	Four resistances of `3Omega, 3Omega, 3Omega and 4Omega` respectively are used to form a Wheatstone bridge. The `4Omega` resistance is short circuited with a resistance R in order to get bridge balanced. The value of R will beA. `10Omega`B. `11Omega`C. `12Omega`D. `13Omega`
Answer» Correct Answer - C The bridge will be balanced when the shunted resistance is of the value of `3Omega` `therefore 3=(4xxR)/(4+R) ,12+3=4R, therefore R=12Omega`

Discussion

2353.	Three resistances `4Omega` each of are connected in the form of an equilateral triangle. The effective resistance between two corners isA. `8 Omega`B. `12 Omega`C. `(3)/(8) Omega`D. `(8)/(3)Omega`
Answer» Correct Answer - D

Discussion

2354.	Three resistance each of `4Omega` are connected to form a triangle. The resistance between any two terminals isA. `12Omega`B. `2Omega`C. `6Omega`D. `(8)/(3)Omega`
Answer» Correct Answer - D

Discussion

2355.	The emf of a cell is 2 V. When the terminals of the cell is connected to a resistance `4Omega`. The potential difference across the terminals, if internal resistance of cell is `1Omega` isA. `(3)/(5)V`B. `(8)/(5)V`C. `(6)/(5)V`D. `(5)/(8)V`
Answer» Correct Answer - B `V=E-ir`

Discussion

2356.	Two cells of emf `1.25V,0.75V` and each of internal resistance `1Omega` are connected in parallel. The effective emf will beA. 1 VB. 1.25 VC. 2 VD. 0.5 V
Answer» Correct Answer - A `E_(eff)=(E_(1)r_(2)+E_(2)r_(1))/(r_(1)+r_(2))`

Discussion

2357.	A galvanometer has 30 divisions and a sensitivity `16 mu A //"div"`. It can be converted into a voltmeter to read `3 V` by connectingA. Resistance nearly `6 k Omega` in seriesB. `6 k Omega` in parallelC. `500 Omega` in seriesD. It cannot be converted
Answer» Correct Answer - A

Discussion

2358.	Voltmeters `V_(1)` and `V_(2)` are connected in series across a `D.C.` line `V_(1)` reads 80 volts and has a per volt resistance of `200 ohms`, `V_(2)` has a total resistance of 32 kilo ohms. The line voltage isA. 120 voltsB. 160 voltsC. 220 voltsD. 240 volts
Answer» Correct Answer - D

Discussion

2359.	Voltmeters `V_(1)` and `V_(2)` are connected in series across a `D.C.` line `V_(1)` reads 80 volts and has a per volt resistance of `200 ohms`, `V_(2)` has a total resistance of 32 kilo ohms. The line voltage is
Answer» Correct Answer - `240V` The resistance `R_(1)` of voltage `V_(1)` is given by `R_(1) = 80 xx 200 = 16000 Omega = 16 k Omega` Current in the circuit `I = (V_(1))/(R_(1)) = (80)/(16000) = 5 xx 10^(-3)A` Reading of second voltmeter `V_(1) = IR_(2) = (5 xx 10^(-3)) xx (32 xx 10^(3)) = 160 V` `:.` Let voltage `V= V_(1) + V_(2) = 80 + 160 = 240 V`

Discussion

2360.	The resistivity of a potentiometer wire is `40xx10^(-8)Omega-m` and its area of cross section is `8xx10^(-6)m^(2)`. If 0.2 A current is flowing through the wire the potential gradient will beA. `10^(-2)V//m`B. `10^(-1)V//m`C. `3.2xx10^(-2)V//m`D. `1V//m`
Answer» Correct Answer - A

Discussion

2361.	Resistivity of potentiometer wire is `10^(-7)` ohm metre and its area of cross-section is `10^(-6)m^2`. When a current `l=0.1A` flows through the wire, its potential gradient is:A. `10^(-2)V//m`B. `10^(-4)V//m`C. 0.1V/mD. 10V/m
Answer» Correct Answer - A

Discussion

2362.	A carbon resistor of `(47 +- 4.7) k Omega` is to be marked with rings of different colours for its identification. The colour code sequence will beA. Green - Orange - Voilet - GoldB. Violet - Yellow - Orange - SilverC. Yellow- Green - Violet - GoldD. Yellow - Violet - Orange - Silver
Answer» Correct Answer - D (d) `R = (47 +- 4.7) xx 10^(3) implies R = 47 xx 10^(3) +- 10^(3) % Omega` As per color code, 3- Orange - Violet - Orange, 4 - Yellow, 7 - Violet 10% silver So current sequence is Yellow - violet - Orange - Silver

Discussion

2363.	The `SI` unit of cunductivity isA. ohmB. mhoC. ohm- mD. `mho-m^(-1)`
Answer» Correct Answer - D

Discussion

2364.	The electric field in the copper wire of area of cross - section `2mm^(2)` carrying a current of `1A` is (use resistivily of copper is `1.7 xx 10^(-8) Omegam)`A. `8.0 xx 10^(-2)Vm^(-1)`B. `8.5 xx 10^(-2)V//m`C. `8.0 xx 10^(-3)V//m`D. `8.0 xx 10^(-4)V//m`
Answer» Correct Answer - C

Discussion

2365.	The resistance of the given carbon resistor is `(24xx10^6+-5%)Omega`. What is the sequence of colours on the strips provided on resistor?
Answer» Correct Answer - B::D `2rarr` Red `4rarr` Yellow `10^6rarr` Blue `5%rarr` Gold

Discussion

2366.	A carbon resistance of `4.7 k Omega` is to be market with strips or hands of different colours for its identification. Write the sequence of colours
Answer» Correct Answer - yellow, violet and red. Resistance `= 4.7 k Omega = 47 xx 10^(2)Omega`. For numbers, 4.7 and 2, the colour are yellow, violet and red.

Discussion

2367.	What will be the bands of colours in sequence on carbon resistor, if its resistance is `0.1 Omega +- 5%`.
Answer» Resistance `= 0.1 Omega +-5% = 01xx10^(-1) +-5%` Thus, the colour of bands in sequence is black, brown and gold. Tolerance of `+-5%` is indicated by gold ring.

Discussion

2368.	The resistance of the given carbon resistor is `(24xx10^6+-5%)Omega`. What is the sequence of colours on the strips provided on resistor?A. red, yellow and goldB. red, yellow , blue and goldC. brown , orange , green and goldD. red,green , yellow and gold
Answer» Correct Answer - A

Discussion

2369.	Determine the voltage drop across the resistance `R_(1)` in the circuit given in Fig. 4.55 with `epsilon=90 V, R_(1)=5 k Omega, R_(2)=5k Omega, R_(3)=10 k Omega " and " R_(4)=10 k Omega`.
Answer» Correct Answer - `50 V`

Discussion

2370.	Assertion : In a simple battery circuit the point of lowest potential is positive terminal of the battery. Reason : The current flows towards the point of the higher potential as it flows in such a circuit from the negative the positive terminal.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 assertionC. If assertion is true but reason is falseD. If the assertion and reason both are false
Answer» Correct Answer - D

Discussion

2371.	Assertion : In a simple battery circuit the point of lowest potential is positive terminal of the battery. Reason : The current flows towards the point of the higher potential as it flows in such a circuit from the negative the positive terminal.A. If both the assertion and reason are true and reason is a true explanation of the assertion.B. If both the assertion and reason are true but the reason is not the correct explanation of assertion.C. If the assertion and reason are falseD. If both the assertion and reason are false.
Answer» Correct Answer - D (d) It is quite clear that in a battery circuit, the point of lowest potential is the negative terminal of the battery and the current flows from higher potential to power potential.

Discussion

2372.	Assertion: The probability of an electric bulb fusing is higher at the time of switching `ON` and `OFF`. Reason: Inductive effects produce a surge at the time of switch `OFF` and switch `ON`.A. If both the assertion and reason are true and reason is a true explanation of the assertion.B. If both the assertion and reason are true but the reason is not the correct explanation of assertion.C. If the assertion and reason are falseD. If both the assertion and reason are false.
Answer» Correct Answer - A (a) The possiblity of an electric bulb fusing is higher at the time of switching `ON` and switching `OFF` because inductive effect produes a surge at the time of switching `ON` and `OFF`.

Discussion

2373.	The resistance across A and B in the figure below will be A. 3RB. RC. `(R)/(3)`D. None of these
Answer» Correct Answer - C

Discussion

2374.	Assertion: The resistivity of a semiconductor increases with temperature. Reason: The atoms of a semiconductor vibrate with larger amplitude at higher temperature therby increasing it resistivity.A. If both the assertion and reason are true and reason is a true explanation of the assertion.B. If both the assertion and reason are true but the reason is not the correct explanation of assertion.C. If the assertion and reason are falseD. If both the assertion and reason are false.
Answer» Correct Answer - D (d) Resistivity of a semiconductor decreases with the temperature. The atoms of a semiconductor vibrate with larger ampliutes at higher temperatures thereby increasing its conductivity not resistivity.

Discussion

2375.	The current (I) and voltage (V) graphs for a given metallic wire at two different temperature `(T_(1))` and `(T_(2))` are shown in fig. It is concluded that A. `T_(1)gtT_(2)`B. `T_(1)ltT_(2)`C. `T_(1)=T_(2)`D. `T_(1)gt2T_(2)`
Answer» Correct Answer - B

Discussion

2376.	The temperature (T) dependence of resistivity (rho) of a semiconductor is represented by :A. B. C. D.
Answer» Correct Answer - C The resistivity of a semiconductor decreases with increase in temperature exponentially. Hence, option (c ) is correct.

Discussion

2377.	A Steady current flows in a metalic conductor of non uniform cross section. The quantity/quantities which remain constant along the length of the conductor is/areA. current electric field ad drift speedB. drift speed onlyC. current and drift speedD. current only
Answer» Correct Answer - D `i=n eAv_(d)` Therefore for non-uniform cross-section (different value of A) drift speed will be different at different sections. Only current (or rate of flow of charge) will be same.

Discussion

2378.	Read the following statements carefully `Y`: The resistivity of semiconductor decreases with increases of temperature. `Z`: In a conducing solid, the rate of collisions between free electrons and joins increases with the increase of temperature.Select the correct statement (`s`) from the following a. `Y` is true but Z is false b.`Y` is false but `Z` is true c.Both `Y` and `Z` are true d. `Y` is true `Z` and `Z` is the correct reason for `Y`
Answer» Resistivity of conductors increases with increase in temperature because rate of collisions between free electrons and ions increase with increase of temperature. However the reistivity of semiconductors decreases with increase in temperature, because more and more covalent bonds are broken at higher temperatures and free electrons increase with increase in temperature. Therefore, the correct option is (c).

Discussion

2379.	The temperature (T) dependence of resistivity (rho) of a semiconductor is represented by :A. B. C. D.
Answer» Correct Answer - C

Discussion

2380.	Read the following statements carefully : Y : The resistivity of a semiconductor decreases with increase of temperature. Z : In a conducing solid, the rate of collisions between free electrons and ions increase with increase of temperature. Select the correct statement (s) from the followin :A. Y is true but Z is falseB. Y is false but Z is trueC. Both Y and Z are trueD. Y is true and Z is the correct reason for Y
Answer» Correct Answer - C Resistivity of conductors increases with increases in temperature because rate of collisions between free electrons and ions increases with increases of tempeature However the resistivity of semiconductors decreases with increase in temperature because more and more covalent bonds are broken at higher temperature.

Discussion

2381.	Read the following statements carefully : Y : The resistivity of a semiconductor decreases with increase of temperature. Z : In a conducing solid, the rate of collisions between free electrons and ions increase with increase of temperature. Select the correct statement (s) from the followin :A. Y is true but Z is falseB. Y is false but Z is true.C. Both Y and Z are trueD.
Answer» Correct Answer - C (c ) The conductivity of a semiconductor increases with increases in temperature i.e. the resistivity decreases with increases in temperature. In a conducting solid, the collisions become more frequent with increase of temperature.

Discussion

2382.	Name the charge carriers in the following at room temperature : (i) Conductor (ii) Intrinsic semiconductor (iii) Insulator.
Answer» (i) Electrons (ii) Electrons and Holes (iii) Electrons and Holes

Discussion

2383.	A uniform wire of resistance `R` is slaped into a regular n-sided polygon (n is seven). The equivalent resistance between any two corners can have :A. the maximum value `R//4`B. the maximum value `R//n`C. the minimum value `R((n - 1)/(n^(2)))`D. the minimum value `R//n`
Answer» Correct Answer - a,c, The resistance of each side of polygon `= R//n`. For maximum resistance between opposite correct we have two resistance each of `R//2` in parallel The maximum resistance `= ((R//2)xx (R//2))/((R//2)+(R//2)) = (R )/(4)` For resistance between adjacent current, we have two resistance `R//n` and `(n- 1) R//n` in parallel Their effective resistance `= ((R//n) xx[(n - 1)R//n])/((R//n) + (n - 1)R//n) = (R(n- 1))/(n^(2))`

Discussion

2384.	Two resistors are connected (a) in series (b) in parallel The equivalent resistance in the two cases are `9 ohm` and `2ohm` respectively. Then the resistances of the component resistor areA. `2 ohm` and `7 ohm`B. `3 ohm` and `6 ohm`C. `3 ohm` and `9 ohm`D. `5 ohm` and `4 ohm`
Answer» Correct Answer - B (b) `R_(1) + R_(2) = 9` and `(R_(1) R_(2))/(R_(1) + R_(2)) = 2 implies R_(1) R_(2) = 18` `R_(1) - R_(2) = sqrt((R_(1) + R_(2))^(2) - 4 R_(1) R_(2)) = sqrt(81 - 72) = 3` `R_(1) = 6 Omega, R_(2) = 3 Omega`

Discussion

2385.	Two wire of the same meta have same length, but their cross-sections are in the rati `3:1` . They are joined in series. The resistance of thicker wire is `10Omega` . The total resistance of the combination will beA. `10Omega`B. `20Omega`C. `40Omega`D. `100Omega`
Answer» Correct Answer - C

Discussion

2386.	Two wires of same metal have the same length but their cross- sections are in the ratio 1 :3 . They are joined in series. The resistance of the thicker wire is `10 Omega` . The total resistance of the combination will beA. `40 Omega`B. `(40)/(3) Omega`C. `(5)/(2) Omega`D. `100 Omega`
Answer» Correct Answer - A

Discussion

2387.	A student has 10 resistors of resistance ‘ r ’. The minimum resistance made by him from given resistors isA. `10 r`B. `(r)/(10)`C. `(r)/(100)`D. `(r)/(3)`
Answer» Correct Answer - B

Discussion

2388.	A student has 10 resistors of resistance ‘ r ’. The minimum resistance made by him from given resistors isA. 10rB. `(r)/(10)`C. `(r)/(100)`D. `(r)/(5)`
Answer» Correct Answer - B

Discussion

2389.	An infinite network of resistances has been made as shown in the figure. Each resistance is R. find the equivalent resistance between A and B.
Answer» Correct Answer - `2R`

Discussion

2390.	n equal resistors are first connected in series and then connected in parallel. What is the ratio of the maximum to the minimum resistance ?A. nB. `1//n^(2)`C. `n^(2)`D. `1//n`
Answer» Correct Answer - C

Discussion

2391.	Referring to the figure below, the effective resistance of the network is A. `2r`B. `4r`C. `10r`D. `5r//2`
Answer» Correct Answer - D

Discussion

2392.	Five equal resistances each of value R are connected in a form shown alongside. The equivalent resistance of the network A. Between the points B and D is RB. Between the points B and D is `(R)/(2)`C. Between the points A and C is RD. Between the points A and C is `(R)/(2)`
Answer» Correct Answer - B::C

Discussion

2393.	In the network shown in figure each resistance is `1Omega` . The effective resistance between A and B is A. `(4)/(3)Omega`B. `(3)/(2)Omega`C. `7Omega`D. `(8)/(7)Omega`
Answer» Correct Answer - D

Discussion

2394.	The effective resistance between points A and C for the network shown figure is A. `(2)/(3)R`B. `(3)/(2)R`C. 2RD. `(1)/(2R)`
Answer» Correct Answer - A

Discussion

2395.	In the given network of resistances, the effective resistance between A and B is A. `(5)/(3)R`B. `(8)/(3)R`C. 5RD. 8R
Answer» Correct Answer - A

Discussion

2396.	An infinite ladder network is arranged with resistances R and 2 R as shown. The effective resistance between terminals A and B is A. `oo`B. RC. 2RD. 3R
Answer» Correct Answer - C

Discussion

2397.	the length of wire of diameter 0.5 mm needed to produce a coil of resistance `10Omega` and specific resistance `4.4xx10^(-7)Omega` m isA. 4.45 mB. 5.55 mC. 5.45 mD. 1.45 m
Answer» Correct Answer - A `R= (rho l)/(A)` `:.l=(10xx3.14xx25xx10^(-8))/(4.4xx10^(-7)xx4)=(78.5)/(17.6)=4.45`m

Discussion

2398.	Two conductors have the same resistance at `0^@C` but their temperature coefficient of resistanc are `alpha_1 and alpha_2`. The respective temperature coefficients of their series and parallel combinations are nearlyA. `alpha_(1)+ alpha_(2) (alpha_(1)+ alpha_(2))/(2)`B. `alpha_(1)+ alpha_(2) (alpha_(1)alpha_(2))/(alpha_(1)+ alpha_(2))`C. `(alpha_(1)+ alpha_(2))/(2), (alpha_(1)+ alpha_(2))/(2)`D. `(alpha_(1)+ alpha_(2))/(2), alpha_(1)+ alpha_(2)`
Answer» Correct Answer - c Let `R_(t_1),R_(t_2)` be the resistance of two combination at temperature `t_(1)^(@)C` temperature Then, `R_(1) =R_(0)(1 + alpha_(1)t)` and `R_(2) =R_(0)(1 + alpha_(1)t)` When conduction are in series let `alpha_(S)` be the effective temperature coeffecient of resistances series Then effective resistance at temperature `t^(@)C` is `R_(1) = R_(t_1) +R_(t_2)` `2R_(0) (1 + alpha_(S)t)= R_(0)(1+ alpha_(1)t) +(1+ R_(0)(1 + alpha_(2)t)` or `2 + 2alpha_(1)t = (1+alpha_(1)t ) +(1+alpha_(2)t)` `= 2 +(alpha_(1)+alpha_(2))t` On solving `alpha_(s) = (alpha_(1) +alpha_(2))/(2)` When conductors are in parallel of resistance in parallel. Then `(1)/(R_(P)) = (1)/(R_(t_1)) + (1)/(R_(t_2))` or `(1)/((R_(0)//2)+[1+alpha_(p)t)) = (1)/(R_(0)(1+alpha_(1)t)) +(1)/(R_(0)(1+alpha_(2)t))` or `(2)/((1+alpha_(P)t)) = (1)/((1+alpha_(1)t)) + (1)/((1+alpha_(2)t))` or `2(1+alpha_(p)t)^(-1)=(1+alpha_(1)t)^(-1)+(1+alpha_(2)t)^(-1)` or `2(1 - alpha_(p)t)0 = ( 1- alpha_(1)t) +(1 - alpha_(2)t)` On solving `alpha_(p) = (alpha_(1) + alpha_(2))/(2)`

Discussion

2399.	The resistance of a coi is `4.2Omega` at `100^(@)C` and the temperature coefficient of resistance of its material is `(0.004)/(.^(@)C)`. Its resistance at `0^(@)C` isA. `6.5Omega`B. `5Omega`C. `3Omega`D. `2.5Omega`
Answer» Correct Answer - C `R_(t)=R_(0)(1+alphat)`

Discussion

2400.	The temperature coefficient of a resistance wire is `0.00 12.5^(@)C^(-1)`. At 300 K, its resistance is `1 Omega`. At what temperature the resistance of the wire will be `2 Omega` ?
Answer» Correct Answer - `1127 K`

Discussion

Explore topic-wise InterviewSolutions in .

Three resistances are connected to form a T-shape as shown in the figure. Then, the current in the `4Omega` resistor is A. `0.93A`B. `4.5A`C. `2.5A`D. `1.57A`

Four resistances of `3Omega, 3Omega, 3Omega and 4Omega` respectively are used to form a Wheatstone bridge. The `4Omega` resistance is short circuited with a resistance R in order to get bridge balanced. The value of R will beA. `10Omega`B. `11Omega`C. `12Omega`D. `13Omega`

Three resistances `4Omega` each of are connected in the form of an equilateral triangle. The effective resistance between two corners isA. `8 Omega`B. `12 Omega`C. `(3)/(8) Omega`D. `(8)/(3)Omega`

Three resistance each of `4Omega` are connected to form a triangle. The resistance between any two terminals isA. `12Omega`B. `2Omega`C. `6Omega`D. `(8)/(3)Omega`

The emf of a cell is 2 V. When the terminals of the cell is connected to a resistance `4Omega`. The potential difference across the terminals, if internal resistance of cell is `1Omega` isA. `(3)/(5)V`B. `(8)/(5)V`C. `(6)/(5)V`D. `(5)/(8)V`

Two cells of emf `1.25V,0.75V` and each of internal resistance `1Omega` are connected in parallel. The effective emf will beA. 1 VB. 1.25 VC. 2 VD. 0.5 V

A galvanometer has 30 divisions and a sensitivity `16 mu A //"div"`. It can be converted into a voltmeter to read `3 V` by connectingA. Resistance nearly `6 k Omega` in seriesB. `6 k Omega` in parallelC. `500 Omega` in seriesD. It cannot be converted

Voltmeters `V_(1)` and `V_(2)` are connected in series across a `D.C.` line `V_(1)` reads 80 volts and has a per volt resistance of `200 ohms`, `V_(2)` has a total resistance of 32 kilo ohms. The line voltage isA. 120 voltsB. 160 voltsC. 220 voltsD. 240 volts

Voltmeters `V_(1)` and `V_(2)` are connected in series across a `D.C.` line `V_(1)` reads 80 volts and has a per volt resistance of `200 ohms`, `V_(2)` has a total resistance of 32 kilo ohms. The line voltage is

The resistivity of a potentiometer wire is `40xx10^(-8)Omega-m` and its area of cross section is `8xx10^(-6)m^(2)`. If 0.2 A current is flowing through the wire the potential gradient will beA. `10^(-2)V//m`B. `10^(-1)V//m`C. `3.2xx10^(-2)V//m`D. `1V//m`

Resistivity of potentiometer wire is `10^(-7)` ohm metre and its area of cross-section is `10^(-6)m^2`. When a current `l=0.1A` flows through the wire, its potential gradient is:A. `10^(-2)V//m`B. `10^(-4)V//m`C. 0.1V/mD. 10V/m

A carbon resistor of `(47 +- 4.7) k Omega` is to be marked with rings of different colours for its identification. The colour code sequence will beA. Green - Orange - Voilet - GoldB. Violet - Yellow - Orange - SilverC. Yellow- Green - Violet - GoldD. Yellow - Violet - Orange - Silver

The `SI` unit of cunductivity isA. ohmB. mhoC. ohm- mD. `mho-m^(-1)`

The electric field in the copper wire of area of cross - section `2mm^(2)` carrying a current of `1A` is (use resistivily of copper is `1.7 xx 10^(-8) Omegam)`A. `8.0 xx 10^(-2)Vm^(-1)`B. `8.5 xx 10^(-2)V//m`C. `8.0 xx 10^(-3)V//m`D. `8.0 xx 10^(-4)V//m`

The resistance of the given carbon resistor is `(24xx10^6+-5%)Omega`. What is the sequence of colours on the strips provided on resistor?

A carbon resistance of `4.7 k Omega` is to be market with strips or hands of different colours for its identification. Write the sequence of colours

What will be the bands of colours in sequence on carbon resistor, if its resistance is `0.1 Omega +- 5%`.

The resistance of the given carbon resistor is `(24xx10^6+-5%)Omega`. What is the sequence of colours on the strips provided on resistor?A. red, yellow and goldB. red, yellow , blue and goldC. brown , orange , green and goldD. red,green , yellow and gold

Determine the voltage drop across the resistance `R_(1)` in the circuit given in Fig. 4.55 with `epsilon=90 V, R_(1)=5 k Omega, R_(2)=5k Omega, R_(3)=10 k Omega " and " R_(4)=10 k Omega`.

The resistance across A and B in the figure below will be A. 3RB. RC. `(R)/(3)`D. None of these

The current (I) and voltage (V) graphs for a given metallic wire at two different temperature `(T_(1))` and `(T_(2))` are shown in fig. It is concluded that A. `T_(1)gtT_(2)`B. `T_(1)ltT_(2)`C. `T_(1)=T_(2)`D. `T_(1)gt2T_(2)`

The temperature (T) dependence of resistivity (rho) of a semiconductor is represented by :A. B. C. D.

A Steady current flows in a metalic conductor of non uniform cross section. The quantity/quantities which remain constant along the length of the conductor is/areA. current electric field ad drift speedB. drift speed onlyC. current and drift speedD. current only

The temperature (T) dependence of resistivity (rho) of a semiconductor is represented by :A. B. C. D.

Name the charge carriers in the following at room temperature : (i) Conductor (ii) Intrinsic semiconductor (iii) Insulator.

A uniform wire of resistance `R` is slaped into a regular n-sided polygon (n is seven). The equivalent resistance between any two corners can have :A. the maximum value `R//4`B. the maximum value `R//n`C. the minimum value `R((n - 1)/(n^(2)))`D. the minimum value `R//n`

Two resistors are connected (a) in series (b) in parallel The equivalent resistance in the two cases are `9 ohm` and `2ohm` respectively. Then the resistances of the component resistor areA. `2 ohm` and `7 ohm`B. `3 ohm` and `6 ohm`C. `3 ohm` and `9 ohm`D. `5 ohm` and `4 ohm`

Two wire of the same meta have same length, but their cross-sections are in the rati `3:1` . They are joined in series. The resistance of thicker wire is `10Omega` . The total resistance of the combination will beA. `10Omega`B. `20Omega`C. `40Omega`D. `100Omega`

Two wires of same metal have the same length but their cross- sections are in the ratio 1 :3 . They are joined in series. The resistance of the thicker wire is `10 Omega` . The total resistance of the combination will beA. `40 Omega`B. `(40)/(3) Omega`C. `(5)/(2) Omega`D. `100 Omega`

A student has 10 resistors of resistance ‘ r ’. The minimum resistance made by him from given resistors isA. `10 r`B. `(r)/(10)`C. `(r)/(100)`D. `(r)/(3)`

A student has 10 resistors of resistance ‘ r ’. The minimum resistance made by him from given resistors isA. 10rB. `(r)/(10)`C. `(r)/(100)`D. `(r)/(5)`

An infinite network of resistances has been made as shown in the figure. Each resistance is R. find the equivalent resistance between A and B.

n equal resistors are first connected in series and then connected in parallel. What is the ratio of the maximum to the minimum resistance ?A. nB. `1//n^(2)`C. `n^(2)`D. `1//n`

Referring to the figure below, the effective resistance of the network is A. `2r`B. `4r`C. `10r`D. `5r//2`

Five equal resistances each of value R are connected in a form shown alongside. The equivalent resistance of the network A. Between the points B and D is RB. Between the points B and D is `(R)/(2)`C. Between the points A and C is RD. Between the points A and C is `(R)/(2)`

In the network shown in figure each resistance is `1Omega` . The effective resistance between A and B is A. `(4)/(3)Omega`B. `(3)/(2)Omega`C. `7Omega`D. `(8)/(7)Omega`

The effective resistance between points A and C for the network shown figure is A. `(2)/(3)R`B. `(3)/(2)R`C. 2RD. `(1)/(2R)`

In the given network of resistances, the effective resistance between A and B is A. `(5)/(3)R`B. `(8)/(3)R`C. 5RD. 8R

An infinite ladder network is arranged with resistances R and 2 R as shown. The effective resistance between terminals A and B is A. `oo`B. RC. 2RD. 3R

the length of wire of diameter 0.5 mm needed to produce a coil of resistance `10Omega` and specific resistance `4.4xx10^(-7)Omega` m isA. 4.45 mB. 5.55 mC. 5.45 mD. 1.45 m

The resistance of a coi is `4.2Omega` at `100^(@)C` and the temperature coefficient of resistance of its material is `(0.004)/(.^(@)C)`. Its resistance at `0^(@)C` isA. `6.5Omega`B. `5Omega`C. `3Omega`D. `2.5Omega`

The temperature coefficient of a resistance wire is `0.00 12.5^(@)C^(-1)`. At 300 K, its resistance is `1 Omega`. At what temperature the resistance of the wire will be `2 Omega` ?