Practice Test

Q1) Which of the cells is easily damaged by the short circuiting ? Show Answer

Q2) The current capacity of a secondary cell is independent of :
Show Answer

Q3) E.M.F. of cell depends upon: Show Answer

Q4) Cells are joined in parallel to get maximum current when: Show Answer

Q5) Cells are joined in series to get maximum current when : Show Answer

Q6) Side-wire bridge is an application of : Show Answer

Q7) Two batteries of different e.m.f. and internal resistance are connected in series with an external resistor and current in circuit is 3 A. When polarity of one is reversed the current is 1 A. The ratio of their e.m.f.'s is : Show Answer

Q8) A piece of a wire is cut into four equal parts and the pieces are bundled together closely to form a thicker wire. Compared with that of the original, the resistance of thicker wire is : Show Answer

Q9) A wire stretched to increase its length by 10 %. What is the percentage increase in resistance ? Show Answer

Q10) External resistance of a circuit is R which is connected to n exactly similar cells. If the current in the circuit is the same whether the cells are in series or in parallel, the value of internal resistance of each cell is : Show Answer

Q11) 12 cells each having same e.m.f. are connected in series and are kept in a closed box. Some of them are wrongly connected. Two identical cells are connected in series to aid this battery and the current is 3 A when circuit is completed through an external resistance. The current is 2 A if the cells are made to oppose the battery through same resistance. The number of cells wrongly connected are: Show Answer

Q12) Kirchhoff's second law is based on the law of conservation of : Show Answer

Q13) For uniform wires with following dimensions, the resistance is least for: Show Answer

Q14) The terminal potential difference of a battery exceeds its e.m.f. when it is connected : Show Answer

Q15) The conductivity of super-conductor is : Show Answer

Q16) The resistance of a discharge tube is : Show Answer

Q17) A man wants to test his ammeter whose range is 0-1 ampere. He connects it to a 12 V storage battery and a carbon resistance of 48 ohm 0.5 watt. Which of the following is most likely to happen ? Show Answer

Q18) A moving coil voltmeter is being used for measuring P.D. across a resistor of resistance r in which a current I is flowing. The voltmeter has a resistance R. The voltmeter will measure the P.D. more correctly as : Show Answer

Q19) An electric current of 5 A is divided into three branches forming parallel combination. The length of wire in the three branches are in the ratio 2:3:4 while their diameters are in the ratio 3:4:5. Find the current in each branch if wires are of the same material. Show Answer

Q20) 36 cells each of internal resistance 0.5 W and e.m.f. 1.5 V each are used to send current through an external circuit of 2 W resistance. Find the best mode of grouping them and current through external circuit. Show Answer

Q21) n identical cells, each e.m.f. E and internal resistance r, are joined in series to form a closed circuit. The potential difference across any one of the cell is : Show Answer

Q22) The current in a copper wire is increased by increasing the potential difference between its ends. Which of the following statements regarding n, the number of charge carries per unit volume in the wire and v, the drift velocity of the charge carries is correct ? Show Answer

Q23) A piece of a wire is cut into four parts and the pieces are bundled together side by side to form a thick wire. Compared with that of the original wire, the resistance of the bundle is : Show Answer

Q24) N identical cells, each e.m.f. E and internal resistance r, are joined in series to form 'a' closed circuit. One cell A is joined with the reverse polarity. The potential difference across each cell except A is : Show Answer

Q25) The masses of three wires of copper are in the ratio 1:3:5 and their lengths are in ratio 5:3:1. The ratio of their electrical resistances is : Show Answer

Q26) The momentum acquired by the electrons in length l of wire a current I starts to flow is : Show Answer

Q27) A current I flows in a wire of circular cross-section with the free electrons traveling with a drift velocity v. The drift velocity of electrons when a current 2 I flows in another wire of twice the radius and of the same material is : Show Answer

Q28) One meter long metallic wire is broken into two unequal parts P and Q. The part P is uniformly extended into another wire R. Length of R is twice the length of P and the resistance of R is equal to that of Q. The ratio of the resistances of P and R is : Show Answer

Q29) Two voltmeters P and Q give the same reading when connected across a resistor X in a current - carrying circuit. But when connected across another resistor Y, the reading comes much lower in P than in Q. If P, Q, X, Y represent the respective resistance, the data shows that : Show Answer

Q30) Two conductors, made of the same material, have lengths L and 2L, but have equal resistances. The two are connected in series in a circuit in which current is flowing. Which of the following is/are correct ? Show Answer

Q31) If an electric current is passed through nerves the man : Show Answer

Q32) n identical cells are joined in series with two cells A and B with reversed polarities e.m.f. of each cell is E and internal resistance is r. Potential difference across cell A or B is (n > 4): Show Answer

Q33) An ammeter with internal resistance 90 ohm reads 1.85 A when connected in a circuit containing a battery and two resistances of 700 ohm and 410 ohm in series. Actual current will be : Show Answer

Q34) Is it possible that any battery has some constant value of e.m.f. but the potential difference between the plates is zero ? Show Answer

Q35) The infinity resistance plug in post-office box has Show Answer

Q36) If a copper wire is stretched to make it 0.1% longer, then the percentage change in resistance is approximately : Show Answer

Q37) When a resistance of 2 ohm is connected across the terminals of a cell, the current is 0.5 A. When the resistance is increased to 5 ohm, the current is 0.25 A. The e.m.f. of the cell is : Show Answer

Q38) For a metallic wire, the ratio V/I ( V = applied potential difference, I = current flowing ) : Show Answer

Q39) Given a current carrying wire of non-uniform cross-section. Which of the following is constant throughout the length of the wire ? Show Answer

Q40) Dimensions of electric current is : Show Answer

Q41) When a lamp is connected in series with a capacitor, then the lamp will : Show Answer

Q42) The internal resistance of a cell is the resistance of : Show Answer

Q43) Two cells when connected in series are balanced on 8 cm on a potentiometer. IF the cells are connected with polarities of one of the cell is reversed, they balance of 2 m. The ratio of e.m.f.'s of the two cells is : Show Answer

Q44) A steady current flows in a metallic conductor of non-uniform cross-section. Which of the following quantity is constant along the conductor ? Show Answer

Q45) Potential difference across the terminals of a battery is 50 V, when 11 A current is drawn. And it is 60 V, 1 A current is drawn. The e.m.f. and internal resistance of battery is : Show Answer

Q46) The drift velocity does not depend upon : Show Answer

Q47) If the radius of the copper wire carrying a current is doubled, the drift velocity of the electrons will : Show Answer

Q48) The electrical conductivity of metal decreases with temperature because : Show Answer

Q49) A number of 100 volt lamps connected in parallel are fed by a 130 V battery having an internal resistance of 2.6 ohm. If the resistance of each lamp is 200 ohm and the resistance of conducting wires is 0.40 ohm, the number of lamps which the battery can light properly is : Show Answer

Q50) A battery of e.m.f. 10 V and internal resistance 0.5 ohm is connected across a variable resistance R. The value of R for which the power delivered in it is maximum is given by : Show Answer

Q51) To convert a galvanometer into voltmeter we must connect a : Show Answer

Q52) The resistance of a conductor increases with : Show Answer

Q53) When a wire of resistance R is stretched and its radius becomes r/2, then new resistance will be : Show Answer

Q54) Kirchhoff's first law is based on the law of conversation of : Show Answer

Q55) A wire resistance R is stretched till its radius is half of the original value. Then the resistance of the stretched wire is : Show Answer

Q56) The drift velocity of free electrons in a conductor is v when a current i is flowing in it. If both the radius and current are doubled, then drift velocity will be : Show Answer

Q57) Which of the following has the largest resistance ? Show Answer

Q58) The resistivity of metal increases with increase in temperature because : Show Answer

Q59) A cell of e.m.f. has a resistance R connected across it, and a voltmeter measures the potential difference across the terminals of the cell as V. The internal resistance of the cell is : Show Answer

Q60) Ohm's law is not obeyed by : Show Answer

Q61) Express which of the following set up can be used to verify Ohm's law ? Show Answer

Q62) In a Wheatstone's bridge, all the four arms have equal resistance R. IF the resistance of the galvanometer arm is also R, the equivalent resistance of the combination as seen by the battery is : Show Answer

Q63) A cell e.m.f. E is connected across a resistance r. The potential difference between the terminals of the cell is found to be V. The internal resistance of the cell must be : Show Answer

Q64) n cells of each e.m.f. E and internal resistance r send the same current through an external resistance R whether the cells are connected in series or in parallel. Then : Show Answer

Q65) Two wires of the same material and the same length are connected to the two gaps of a meter bridge. The balancing length measured from left is 25 cm. The ratio of radius of the wire in the left gap to that in the right gap is : Show Answer

Q66) When a current is divided between two resistors according to Kirchhoff's law, then the heat produced is : Show Answer

Q67) The electric resistance of a certain wire of iron is R. If its length and radius both doubled, then its Show Answer

Q68) Resistance n each of r ohm, when connected in parallel combination, give an equivalent resistance of R. If these resistances are connected in series, then the new combination would have a resistance equal to : Show Answer

Q69) Current provided by a battery is maximum when : Show Answer

Q70) Which of the following has negative temperature coefficient of resistance ? Show Answer

Q71) For measuring the voltage of any circuit, the potentiometer is preferred to the voltmeter because : Show Answer

Q72) In order to pass 10 % of main current through a moving coil galvanometer of 99 ohm, the resistance of the required shunt is : Show Answer

Q73) A cell of negligible resistance and e.m.f. 2 volt is connected to series combination of 2, 3 and 5 ohm. The P.D. in volt between the terminals of 3 ohm resistance will be : Show Answer

Q74) A wire is wound in the form of a solenoid or length l and diameter d. When a strong current is passed through the solenoid, there is tendency to : Show Answer

Q75) The length of the wire is doubled. Its conductance will be : Show Answer

Q76) When a wire of uniform cross-section a, length l and resistance R is bent into complete circle, resistance between any two diametrically opposite points will be : Show Answer

Q77) The dimensions of electrical resistance are: Show Answer

Q78) To draw maximum current from a combination of cells, how should the cells be grouped ? Show Answer

Q79) A wire is cut into 4 pieces, which are put together by sides so obtain one conductor. If the original resistance of wire was R, the resistance of the bundle will be : Show Answer

Q80) Ohm's law is true : Show Answer

Q81) A voltmeter has a resistance of G ohm and range V volt. The value of resistance used in series to convert it into a voltmeter of range nV volt is : Show Answer

Q82) Two bulbs of equal wattage, one having carbon filament and the other having a tungsten filament are connected in series to the mains, then : Show Answer

Q83) Dimensions of resistance in an electrical circuit, in terms of dimensions of mass M, of length L, of time T and of current I, would be : Show Answer

Q84) A galvanometer acting as a voltmeter will have : Show Answer

Q85) A wire with a certain material is stretched slowly by ten per cent. Its new resistance and specific resistance becomes respectively : Show Answer

Q86) A galvanometer has a coil of resistance 100 ohm and gives a full scale deflection for 30 m A current. If it is to work as a voltmeter of 30 volt range, the resistance required to be added will be : Show Answer

Q87) Consider following statements :
(1) Kirchhoff's junction law follows from the conservation of charge.
(2) Kirchoff's loop law from the conservation of energy.
Which of the following is correct ? Show Answer

Q88) Two wires A and B are made of copper. Both wires are 1 meter long but wire A is 1 mm thick and wire B is 2 mm thick. The specific resistance is : Show Answer

Q89) When a potential difference V is applied across a conductor at temperature T, the drift velocity of electron is proportional to : Show Answer

Q90) When a potential difference V is applied across a conductor at temperature T, the thermal speed of electron is proportional to : Show Answer

Q91) The non ohmic device which exhibits a region of negative resistance is : Show Answer

Q92) An electric bulb has a rating of 500 W, 100 V. It is used a circuit having a 200 V supply. What resistance must be connected in series with the bulb so that it delivers 500 W ? Show Answer

Q93) For accurate measurements, the resistance of a voltmeter should be Show Answer

Q94) The resistance of a straight conductor does not depend on its Show Answer