A current carrying rectangular loop P Q R S is made of uniform wire. The length P R=Q S=5 cm and P Q=R S=100 cm. If ammeter current reading changes from I to 2 I, the ratio of magnetic forces per unit length on the wire P Q due to wire R S in the two cases respectively (fP QI: fP Q2 I) is:

Question

A current carrying rectangular loop P Q R S is made of uniform wire. The length P R=Q S=5 cm and P Q=R S=100 cm. If ammeter current reading changes from I to 2 I, the ratio of magnetic forces per unit length on the wire P Q due to wire R S in the two cases respectively (fP QI: fP Q2 I) is: (A) 1: 5 (B) 1: 3 (C) 1: 2 (D) 1: 4

Tardigrade Admin · Accepted Answer

F propto I 1 I 2 F 1: F 2 I =1: 4

$1 : 5$

$1 : 3$

$1 : 2$

$1 : 4$

$F \propto I_{1} I_{2}$
$F_{1} : F_{2 I} = 1 : 4$

Q. A current carrying rectangular loop PQRS is made of uniform wire. The length PR=QS=5cm and PQ=RS=100cm. If ammeter current reading changes from I to 2I, the ratio of magnetic forces per unit length on the wire PQ due to wire RS in the two cases respectively (fPQI​:fPQ2I​) is:

1:5

1:3

1:2

1:4

F∝I1​I2​ F1​:F2I​=1:4

$1 : 5$

$1 : 3$

$1 : 2$

$1 : 4$

$F \propto I_{1} I_{2}$
$F_{1} : F_{2 I} = 1 : 4$