A millivoltmeter of \(25~\text{mV}\) range is to be converted into an ammeter of \(25~\text{A}\) range. The value (in ohm) of the necessary shunt will be:
1. \(0.001\)
2. \(0.01\)
3. \(1\)
4. \(0.05\)
A current-carrying closed loop in the form of a right isosceles triangle ABC is placed in a uniform magnetic field acting along with AB.
If the magnetic force on the arm BC is F, then what is the force on the arm AC?
1. | -F | 2. | F |
3. | 2F | 4. | -2F |
A uniform electric field and a uniform magnetic field are acting in the same direction in a certain region. If an electron is projected in the region such that its velocity is pointed along the direction of fields, then the electron:
1. speed will decrease
2. speed will increase
3. will turn towards the left of the direction of motion
4. will turn towards the right of the direction of motion
A beam of cathode rays is subjected to cross Electric (E) and magnetic fields(B). The fields are adjusted such that the beam is not deflected. The specific charge of the cathode rays is given by:
1.
2.
3.
4.
(where V is the potential difference between cathode and anode)
A galvanometer has a coil resistance of 100 Ω and gives a full-scale deflection for 30 mA of current. If it is to work as a voltmeter in the 30 V range, how much resistance does it require to be added?
1. 900
2. 1800
3. 500
4. 1000
A square current-carrying loop is suspended in a uniform magnetic field acting in the plane of the loop. If the force on one arm of the loop is \( \overrightarrow{F}\), what will be the net force on the remaining three arms of the loop?
1. | \(3 \overrightarrow{F}\) | 2. | \(- \overrightarrow{F}\) |
3. | \(-3 \overrightarrow{F}\) | 4. | \( \overrightarrow{F}\) |
Under the influence of a uniform magnetic field, a charged particle moves with constant speed \(v\) in a circle of radius \(R.\) The time period of rotation of the particle:
1. | depends on \(v\) and not on \(R.\) |
2. | depends on R and not on \(v.\) |
3. | is independent of both \(v\) and \(R.\) |
4. | depends on both \(v\) and \(R.\) |
1. | 8 N in - z-direction. |
2. | 4 N in the z-direction. |
3. | 8 N in the y-direction. |
4. | 8 N in the z-direction. |
1. | Putting in parallel, a resistance of \(24~ \Omega\) |
2. | Putting in series, a resistance of \(15~ \Omega\) |
3. | Putting in series, a resistance of \(240~ \Omega\) |
4. | Putting in parallel, a resistance of \(15~ \Omega\) |
A closed-loop PQRS carrying a current is placed in a uniform magnetic field. If the magnetic forces on segments PS, SR, and RQ are F1, F2, and F3 respectively, and are in the plane of the paper and along the directions shown,
then which of the following forces acts on the segment QP?
1.
2.
3.
4.