Related InterviewSolutions

• A potentiometer wire of length 20 m has a resistance of 50 ohms. It is connected in series with a resistance box and a 5 V storage cell. If the potential gradient along the wire is 0.5 mV/cm, what is the resistance unplugged in the box?(a) 450 ohms(b) 400 ohms(c) 405 ohms(d) 500 ohmsThe question was asked by my school principal while I was bunking the class.The origin of the question is Current Electricity in section Current Electricity of Physics – Class 12
• A potentiometer has uniform potential gradient. The specific resistance of the material of the potentiometer wire is 10^-9Ωm and the current passing through it is 0.5A and the cross sectional area of the wire is 10^-8m^2. Calculate the potential gradient along the potentiometer wire.(a) 0.5 × 10^-9 V/m(b) 0.5 × 10^-8 V/m(c) 0.5 × 10^-1 V/m(d) 0.5 × 10^-15 V/mI got this question at a job interview.The query is from Current Electricity in chapter Current Electricity of Physics – Class 12
• The balancing length of a potentiometer is at 120 cm. On shunting the cell with a resistance of 4 ohms, the balancing point shifts to a length of 60 cm. Then, find the internal resistance of the cell.(a) 2 ohms(b) 5 ohms(c) 3 ohms(d) 4 ohmsI got this question during an interview.My query is from Current Electricity topic in portion Current Electricity of Physics – Class 12
• A resistance of 5 ohms is connected across the gap of a Meter Bridge and an unknown resistance, greater than 5 ohms, is connected across the other gap. When these resistances are interchanged, the balance point shifts by 50 cm. Neglecting any correction, what is the unknown resistance? The length of the wire is 150 cm.(a) 3 ohms(b) 10 ohms(c) 7 ohms(d) 5 ohmsI got this question in an online interview.This is a very interesting question from Current Electricity in section Current Electricity of Physics – Class 12
• What is the effect on null deflection of galvanometer, when the radius of the wire is tripled?(a) No change(b) Becomes half(c) Reduces by \(\frac {1}{3}\)(d) Thrice the original valueI have been asked this question in exam.I'd like to ask this question from Current Electricity in division Current Electricity of Physics – Class 12
• Find the false statement.(a) Wheatstone bridge is analogous to simple level system(b) A galvanometer with low resistance in series is an ammeter(c) Wheatstone bridge cannot be used forprecision measurement because of the error introduced in contact resistance(d) Wheatstone bridge is susceptible to high dc currentThe question was posed to me in final exam.Question is from Wheatstone Bridge topic in chapter Current Electricity of Physics – Class 12
• Identify the correct statement from the following.(a) While traversing in a closed loop, if negative pole of cell is encountered first, then the emf is negative(b) The product of resistance and current in an arm is taken to be positive if the direction of current is opposite to the direction in which one moves along the closed loop(c) Current flowing away from a junction is taken as positive(d) While traversing in a closed loop, if positive pole of cell is encountered first, then the emf is positiveI have been asked this question by my school teacher while I was bunking the class.I want to ask this question from Kirchoff’s Law in chapter Current Electricity of Physics – Class 12
• Two resistances are connected in two gaps of Meter Bridge. The balance is 20cm from the zero end. A resistance of 15 ohms is connected in series with the smaller of the two. The null point shifts to 40cm. What is the value of the bigger resistance?(a) 9(b) 18(c) 27(d) 36The question was asked in an interview for internship.My question is from Current Electricity topic in portion Current Electricity of Physics – Class 12
• Identify the definition of sensitivity of a galvanometer from the following.(a) Ratio of unit change in unknown resistance to the deflection in the galvanometer(b) Ratio of unit change in unknown resistance to twice the deflection in the galvanometer(c) Ratio of deflection in the galvanometer to the unit change in unknown resistance(d) Ratio of deflection in the galvanometer to half the unit change in unknown resistanceThis question was posed to me at a job interview.The above asked question is from Wheatstone Bridge topic in portion Current Electricity of Physics – Class 12
• Find the false statement.(a) Sum of voltage over any closed loop is zero(b) Kirchhoff’s Laws can be applied to any circuit, regardless of its structure and composition(c) Kirchhoff’s 2^nd law is applied at nodes(d) Kirchhoff’s 1^st law can be applied for both planar and non-planar circuitsThis question was addressed to me in an online interview.My question is from Kirchoff’s Law topic in division Current Electricity of Physics – Class 12