The SI unit of linear charge density is:

Figure shows the cross-sectional view of the hollow cylindrical conductor with inner radius 'R' and outer radius '2R', cylinder carrying uniformly distributed current along it's axis. The magnetic induction at point 'P' at a distance from the axis of the cylinder will be

(a) Zero

(b)

(c)

(d)

→

The engine of a train sounds a whistle at frequency v. The frequency heard by a passenger is:

$>\text{v}$
$<\text{v}$
$=\frac{1}{\text{v}}$
$=\text{v}$

→

The resistance of hot tungsten filament is about 10 times the cold resistance. What will be the resistance of 100 W and 200 V lamp when not in use

(a) 400 Ω

(b) 200 Ω

(d) 20 Ω

→

The device is based on the principle of mutual induction is:

→

Five balls numbered 1 to 5 are suspended using separate threads. Pairs (1, 2), (2, 4) and (4, 1) show electrostatic attraction, while pair (2, 3) and (4, 5) show repulsion. Therefore ball 1 must be

(a) Positively charged

(b) Negatively charged

(d) Made of metal

→

The magnetic flux linked with a coil is given by an equation ∅ (in webers) = . The induced e.m.f. in the coil at the fourth second will be