A uniform wire is resistance 4Ω is bent into the form of a circle of radius r. A specimen of the same wire is connected…..

Q. A uniform wire is resistance 4Ω is bent into the form of a circle of radius r. A specimen of the same wire is connected along the diameter of the circle. What is the equivalent resistance across the ends of this wire?

(a) \displaystyle \frac{4}{(4 + \pi)}

(b) \displaystyle \frac{3}{(3 + \pi)}

(c) \displaystyle \frac{2}{(2 + \pi)}

(d) \displaystyle \frac{1}{(1 + \pi)}

Ans: (a)

In the circuit shown, the voltage drop across the 15Ω resistor is 30 V having the polarity as indicated…..

Q. In the circuit shown, the voltage drop across the 15Ω resistor is 30 V having the polarity as indicated. The ratio of potential difference across 5Ω resistor and resistance R is
Current Electricity
(a) 2/7
(b) 0.4
(c) 5/7
(d) 1
Ans: (d)

A source of emf E = 10V and having negligible internal resistance is connected to a variable resistance…..

Q. A source of emf E = 10V and having negligible internal resistance is connected to a variable resistance. The resistance varies as shown in figure. The total charge that has passed through the resistor R during the time interval from t1 to t2 is

Current Electricity

(a) 40 loge 4

(b) 30 loge 3

(c) 20 loge 2

(d) 10 loge 2

Ans: (d)