Current Electricity

Two resistors of 200 Ω and 400 Ω are connected in series with a battery of 100 V. A bulb rated at 200 V, 100 W is connected across the 400 Ω resistance. The potential drop across the bulb is V.

1. 25
2. 50
3. 66.6
4. 100

Two resistors of 100 each are connected in series with a 9 V battery. A voltmeter of 400 resistance is connected to measure the voltage drop across one of the resistors. The voltmeter reading is V.

1. 3
2. 2
3. 4
4. 4.5

The reading of the ammeter (A) in steady state in the following circuit (assuming negligible internal resistance of the ammeter) is A. [figure]

1. 1/2
2. 1
3. 2
4. 0

A wire of uniform resistance /m is bent into a circle of radius r and another piece of wire with length 2r is connected between points A and B (AOB) as shown in figure. The equivalent resistance between points A and B is . [figure]

1. ( + 1)2r
2. 6 r3 + 16
3. 3 r8
4. 2 r

Two known resistances of R and 2R and one unknown resistance X are connected in a circuit as shown in the figure. If the equivalent resistance between points A and B in the circuit is X , then the value of X is . [figure]

1. 2( 3 - 1)R
2. R
3. ( 3 - 1)R
4. ( 3 + 1)R

A wire of resistance R is bent into a triangular pyramid as shown in figure with each segment having same length. The resistance between points A and B is R/n. The value of n is : [figure]

1. 16
2. 10
3. 12
4. 14

From the combination of resistors with resistance values R1 = R2 = R3 = 5 and R4 = 10 , which of the following combination is the best circuit to get an equivalent resistance of 6 ?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

A wire of length 25 m and cross-sectional area 5 mm2 having resistivity of 2 10-6 m is bent into a complete circle. The resistance between diametrically opposite points will be

1. 100
2. 2.5
3. 12.5
4. 50

In the figure shown below, a resistance of 150.4 is connected in series to an ammeter A of resistance 240 . A shunt resistance of 10 is connected in parallel with the ammeter. The reading of the ammeter is mA. [figure]

Find the equivalent resistance between two ends of the following circuit [figure]

1. r
2. r6
3. r3
4. r9

A wire of resistance R is bent into an equilateral triangle and an identical wire is bent into a square. The ratio of resistance between the two end points of an edge of the triangle to that of the square is

1. 8/9
2. 9/8
3. 32/27
4. 27/32

A wire of resistance 9 is bent to form an equilateral triangle. Then the equivalent resistance across any two vertices will be ohm.

Refer to the circuit diagram given in the figure. which of the following observations are correct? [figure] Choose the correct answer from the options given below:

1. B, C and E Only
2. A, C and D Only
3. A, B and C Only
4. A, B and D Only

Sliding contact of a potentiometer is in the middle of the potentiometer wire having resistance Rp=1 as shown in the figure. An external resistance of Re=2 is connected via the sliding contact. The electric current in the circuit is : [figure]

1. 1.35 A
2. 0.9 A
3. 1.0 A
4. 0.3 A

The net current flowing in the given circuit is A. [figure]