A electric tea kettle has two heating coils. When first coil of resistance R1 is switched on, the kettle begins to boil tea in 6 minutes. When second coil of resistance R2 is switched on, the boiling begins in 8 minutes. The value of R 1 / R 2 is

Question

A electric tea kettle has two heating coils. When first coil of resistance R1 is switched on, the kettle begins to boil tea in 6 minutes. When second coil of resistance R2 is switched on, the boiling begins in 8 minutes. The value of R 1 / R 2 is (A) (7/3) (B) (3/7) (C) (3/4) (D) (4/3)

Tardigrade Admin · Accepted Answer

Heat supplied =( V 2/ R ) × t ⇒ (t1/R1)=(t2/R2) ⇒ (6/R1)=(8/R2) ⇒ (R1/R2)=(3/4)

Q. A electric tea kettle has two heating coils. When first coil of resistance $R_{1}$ is switched on, the kettle begins to boil tea in 6 minutes. When second coil of resistance $R_{2}$ is switched on, the boiling begins in 8 minutes. The value of $R_{1} / R_{2}$ is

$\frac{7}{3}$

$\frac{3}{7}$

$\frac{3}{4}$

$\frac{4}{3}$

Heat supplied $= \frac{V ^{2}}{R} \times t$
$\Rightarrow \frac{t _{1}}{R _{1}} = \frac{t _{2}}{R _{2}}$
$\Rightarrow \frac{6}{R _{1}} = \frac{8}{R _{2}}$
$\Rightarrow \frac{R _{1}}{R _{2}} = \frac{3}{4}$

Q. A electric tea kettle has two heating coils. When first coil of resistance R1​ is switched on, the kettle begins to boil tea in 6 minutes. When second coil of resistance R2​ is switched on, the boiling begins in 8 minutes. The value of R1​/R2​ is

37​

73​

43​

34​