Which of the following statements are true? a) the induced emf in acircuit is equal to the negative of the magnetic flux through thecircuit. b) there can be a nonzeroinduced emf at an instant when the flux through the circuit isequal to zero. c) the self-inductance of asolenoid is proportional to the rate of change of the current inthe solenoid. d) the magnetic energydensity at some point in space is proportional to the square of themagnitude of the magnetic field at that point. e) the inductance of asolenoid is proportional to the current in it.

B) and D)

Explanation:

The correct statement is B) and D)

The induced emf in a loop depends upon the rate of change of flux.

The rate of Emf flux will be zero if the flux through the coil is constant with respect to time otherwise the induced emf will be zero if the magnetic flux through the loop will be zero at any instant.

inductance formula

hence inductance of a solenoid is not proportional to current. so, option E is not right.

magnetic intensity is directly proportional to square of magnetic field statement is correct.

the best answer for these questions would be:

1.            c. is smaller

2.            d) concrete operational

3.            b) interaction with the environment – the children interact with their environment can them learn more.

4.            a) parents who reason openly with children can limit a child’s cognitive ability.