Combination of resistors

Q.

What is meant by effective resistance?

Q.

Four resistors of 4 ohm each are connected in parallel, four such combinations are then connected in series. Their total resistance is

1. 12 Ω

2. 4 Ω

3. 20 Ω

4. 16 Ω

Q. What is the difference between voltage, electromotive force and potential difference?

Q. State true or false.
In the following circuit, the wire parallel to resistor R does not have any resistance. Then, all the current will pass through the resistor R.

1. True
2. False

Q.

Which of the following components will be in parallel?

1. R1, R2 AND V

2. R1 AND R2 ONLY

3. R2 AND V ONLY

4. R1 AND V ONLY

Q.

Two resistors of resistance 5Ω and 15Ω are connected in parallel to a 15 volt battery. Find the current across 5Ω resistor.

1. 3A

2. 1A

3. 4A

4. 2A

Q.

Two resistances $R_1$ and $R_2$ give a combined resistance of 4.5 $\Omega$ when in series and 1 $\Omega$ when in parallel. The value of resistances are___________.​

1. 3 , 6

2. 3 , 9

3. 1.5 , 0.5

4. 1.5 , 3

Q.

A battery of 9 v is connected in series with resistance of 0.2Ω, 0.3Ω, 5Ω, 0.5Ωand12Ω respectively. How much current would flow through the 12Ω resistor?

1. 2 A

2. 1 A

3. 0.5 A

4. 3 A

Q.

When do we say that 2 resistors are in parallel?

1. When P.d. is different

2. When P.d. is same

3. When current is same

4. can’t say

Q. Solve
Question 55.
Two resistor of resistance 5$\Omega$ and 10$\Omega$ are connected to an electrical source. These resistance will have -
(A) Same current flowing through them when connected in parallel
(B) Same current flowing through them when connected in Series
(C) Same Potential difference across them when connected in Series
(D) None of these

Q.

If four resistors, each of the value 0.5 ohm are connected in series, then the total resistance of the circuit is

1. 0.125 Ω

2. 4 Ω

3. 5 Ω

4. 2 Ω

Q. I have a circuit in which the battery can provide a potential difference of 12V and a small motor that can handle a maximum potential difference of 6 volts. In order to get the desired voltage, I would connect a resistor in parallel with the motor, and connect that combination to the terminals of the battery. The motor will work fine without any damage. State True or False.

1. True
2. False

Q.

A wire of resistance 20 ohm is bent in form of a circle. Find the equivalent resistance between two diametrically opposite ends.

1. 40 ohm

2. 20 ohm

3. 10 ohm

4. 5 ohm

Q. When an ideal conductor connects two points, the potential difference between the two points becomes ___.

Q. Which circuit represents a series combination of resistors?
i)

ii)

1. i) only
2. ii) only
3. i) and ii)
4. Neither i) nor ii)

Q.

A circuit contains two unequal resistances in parallel. Which of the following statements is true?

1. Current is more through the larger resistance.

2. The potential difference across each resistor is same.

3. Current is same through both the resistances.

4. Smaller resistance has smaller conductance.

Q.

The effective resistance of a parallel circuit will be lesser than the smallest resistance in the circuit.

1. False

2. True

Q.

The equivalent resistance between (a) & (b) in the circuit can be obtained by the expression:

1. $\frac{1}{R_{eq}}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}+\frac{1}{R_4}$

2. $\frac{1}{R_{eq}}=\frac{1}{R_1}-\frac{1}{R_2}-\frac{1}{R_3}-\frac{1}{R_4}$

3. $R_{eq}=R_1+R_2+R_3+R_4$

4. $R_{eq}=R_1-R_2-R_3-R_4$

Q.

Find the equivalent resistance between A & B in the circuit given below.

1. $18\Omega$
2. $16.5\Omega$
3. $49\Omega$
4. $8.5\Omega$

Q. When n resistors of resistance R each is connected in series, the effective resistance is ___ and when they are connected in parallel, their effective resistance is ___.

1. $n\times R,n\times R$
2. $n\times R,\frac{R}{n}$
3. $\frac{R}{n},n\times R$
4. $\frac{R}{n},\frac{R}{n}$