Exams › JEE Advanced › Physics

Two statements are given below, one as Assertion A and the other as Reason R. Assertion A: Alloys like constantan and manganin are employed to make standard resistance coils. Reason R: Constantan and manganin possess a very low temperature coefficient of resistance. Select the correct option.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is NOT the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Correct answer: Both A and R are true and R is the correct explanation of A.

Solution

Both statements are true and R correctly explains A: a very small temperature coefficient keeps the resistance almost unchanged, which is exactly why these alloys are chosen for standard coils.

Related JEE Advanced Physics questions

• The electric current in a conductor varies with time according to i = (20 + 4t). Determine the value of x if the total charge passing through a section of the conductor in 10 seconds is x × 10² C.
• A 2.0 V potentiometer is used to find the internal resistance of a 1.5 V cell. With the cell's external circuit open, the balance length is 76.3 cm. When a resistor of 9.5 ohm is connected across the cell's terminals, the balance length drops to 64.8 cm. Determine the internal resistance of the cell (give the nearest integer value in ohm).
• In a circuit, resistors of 2 ohm, 3 ohm and 4 ohm are connected in parallel across a battery of EMF 12 V and negligible internal resistance. Which resistor dissipates the maximum power?
• An ideal cell of EMF 10 V and a non-ideal cell of EMF 15 V with internal resistance 1 ohm are connected in parallel between terminals A and B. What is the equivalent EMF between A and B?
• In a Wheatstone bridge, resistors R1 and R2 occupy two adjacent arms while capacitors C1 and C2 occupy the other two adjacent arms. When a key is pressed the galvanometer shows no deflection. Which of the following expressions correctly represents the balance condition for this bridge?
• In a potentiometer circuit used to measure an unknown resistance R, the balance (null) point is found at length PJ = 30 cm when a secondary cell of EMF Es = 10 V and internal resistance r = 1 ohm is used. When the secondary cell is replaced by another with Es = 5 V and r = 2 ohm, the balance point shifts to PJ = 10 cm. What is the value of R (in ohm)?

⚔️ Practice JEE Advanced Physics free + battle 1v1 →