Jharkhand Board Physics Magnetic effect of current MCQs Very Important Verma Guess Paper | Day 5

A brilliant student of physics developed a magnetic balance to weight objects. The mass m to be measured is hung from the center the bar. Bar is kept in a uniform magnetic field of 1.5 T directed into the plane of the figure. Battery voltage can be adjusted to vary the current in the circuit. The horizontal bar shown is 60cm long and is made of extremly light weight material. It is connected to the battery via a resistance. There is no tension in the supporting wired. The magnetic force only supports the hanging weight. If V = 150 V , what is the maximum mass m ?

A brilliant student of physics developed a magnetic balance to weight objects. The mass m to be measured is hung from the center the bar. Bar is kept in a uniform magnetic field of 1.5 T directed into the plane of the figure. Battery voltage can be adjusted to vary the current in the circuit. The horizontal bar shown is 60cm long and is made of extremly light weight material. It is connected to the battery via a resistance. There is no tension in the supporting wired. The magnetic force only supports the hanging weight. Which point of battery is positive?

Two long parallel wires carry currents in opposite direction as shown. Points A and D lie in the same plane as the wires. The magnetic field at A and D is into the plane of the paper, with intensity B_(A) and B_(D) respectively. If (B_(A))/(B_(D))=7/5 , the value of (I_(1))/(I_(2)) is ____________________.

Space is divided by the line AD into two regions. Region I is field free and the Region II has a unifrom magnetic field B direction into the plane of the paper. ACD is a simicircular conducting loop of radius r with center at O, hte plane of the loop being in the plane of the paper. The loop is now made to rotate with a constant angular velocity omega about an axis passing through O and the perpendicular to the plane of the paper. The effective resistance of the loop is R. (i) obtain an expression for hte magnitude of the induced cureent in the loop. (ii) Show the direction of the current when the loop is entering into the Rigion II. Plot a graph between the induced e.m.f and the time of roation for two periods or rotation.

Space is divided by the line AD into two regions. Region I is field free and the Region II has a unifrom magnetic field B direction into the plane of the paper. ACD is a simicircular conducting loop of radius r with center at O, hte plane of the loop being in the plane of the paper. The loop is now made to rotate with a constant angular velocity omega about an axis passing through O and the perpendicular to the plane of the paper. The effective resistance of the loop is R. (i) obtain an expression for hte magnitude of the induced cureent in the loop. (ii) Show the direction of the current when the loop is entering into the Rigion II. Plot a graph between the induced e.m.f and the time of roation for two periods or rotation.