Q. A conducting ring is placed around the core of an electromagnet as shown in fig. When key K is pressed, the ring: (Consider the ring is light weight)
- Is attracted towards the electromagnet.
- Jumps out of the core.
- Revolves around the core.
- Remains stationary.
Q. Two identical coaxial circular loops carry current i each circulating in the clockwise direction. If the loops are approaching each other, then:
- The net current in each loop increases.
- The net current in one loop increases but it decreases in the other.
- The net current in each loop remains the same.
- The net current in each loop decreases.
Q. A magnet NS is suspended from a spring and while it oscillates, the magnet moves in and out of the coil C. The coil is connected to a galvanometer G. Then as the magnet oscillates,
- G shows deflection on one side
- G shows no deflection.
- G shows deflection to the left and right but the amplitude steadily decreases.
- G shows deflection to the left and right with constant amplitude
Q. An electron moves along the line AB, which lies in the same plane as a circular loop of conducting wires as shown in the diagram. What will be the direction of current induced if any, in the loop
- The current will be clockwise.
- No current will be induced.
- The current will be anticlockwise.
- The current will change direction as the electron passes by.
Q. A coil having n turns and resistance R Ω is connected with a galvanometer of resistance 4RΩ . This combination is moved in time t seconds from a magnetic field W1 weber to W2 weber. The induced current in the circuit is
Q. An electron moves on a straight line path 'XY' as shown. The 'abcd' is a coil adjacent to the path of electron. What will be the direction of current, if any, induced in the coil?
- No current induced
- The current will reverse its direction as the electron goes past the coil
Q. The direction of induced current or the polarity of induced emf can be found by
- Amber’s law
- Kirchoff's law
- Lenz’s law
- Lorentz’s law
Q. A bar magnet is thrown along the axis of a ring with speed v0. After sometime, speed of magnet is v, then
- Information is incomplete
Q. A small magnet M is allowed to fall through a fixed horizontal conducting ring R. Let g be the acceleration due to gravity. The acceleration of M will be
- <g when it is above R and moving toward R.
- >g when it is above R and moving toward R.
- <g when it is below R and moving away from R.
- >g when it is below R and moving away from R.
Q. A wire is bent to form the double loop as shown in the figure. There is a uniform magnetic field directed into the plane of the loop. If the magnitude of this field is decreasing, the current will flow from
- B to A and D to C
- A to B and C to D
- A to B and D to C
- B to A and C to D