Question
A conductor of length $$0.4\,m$$ is moving with a speed of $$7\,m/s$$ perpendicular to a magnetic field of intensity $$0.9\,Wb/{m^2}.$$ The induced emf across the conductor is
A.
$$1.26\,V$$
B.
$$2.52\,V$$
C.
$$5.04\,V$$
D.
$$25.2\,V$$
Answer :
$$2.52\,V$$
Solution :
Given, length of conductor $$\left( l \right) = 0.4\,m$$
speed $$\left( v \right) = 7\,m/s$$
Magnetic field $$\left( B \right) = 0.9\,Wb/{m^2}$$
Induced emf, $$e = Blv\sin \theta \,\,\left[ {\theta = {{90}^ \circ }\,{\text{as}}\,B\,{\text{is}}\, \bot \,v} \right]$$
$$\eqalign{
& = 0.9 \times 0.4 \times 7 \times \sin {90^ \circ } \cr
& = 2.52\,V \cr} $$