100Ω
200Ω
300Ω
500Ω
Correct answer is B
Power of the lamp = 60W;
\(I = {\frac{P}{V}}\)
\(I = {\frac{60}{120}}\) = \(0.5A\)
\(R = {\frac{V}{I}}\)
\(R_mains\) = \(\frac{220}{0.5}\) = \(440\Omega\)
\(R_lamp\) = \(\frac{120}{0.5}\) = \(240\Omega\)
\(\therefore\) The non-inductive resistance to keep the lamp = \((440 - 240)\Omega\)
= \(200\Omega\)
Lenz's law is a law of conservation of
electric charge
electric current
Energy
Momentum
Correct answer is C
Lenz's lew of electrical magnetic induction is usefully referred to as the law of conservation of energy
3 x 10-5
3 x 10-6
5 x 105
5 x 10-5
Correct answer is D
since the wires are parallel to each other, the forces which they exert on each other are equal and opposite, since they must agree with newton's law of action an reaction. Hence the force exerted by the wire is equally
5 x 10-5
The instrument that measures both ac and dc is called
A current balance
a moving coil ammeter
a moving iron ammeter
an inverter
Correct answer is C
No explanation has been provided for this answer.
4.0 x 102W
5.0 x 102W
4.0 x 103W
5.0 x 103W
Correct answer is D
In general, Power = IV; \( \implies 40KW = IV \\
\text{Therefore } 40000 = 1 \times 800\\
\implies I = \frac{40000}{800} = 50A,\text{tune the current through} \)
Resistor = 50A
power loss= I2R = 502 x 2
= 2500 x 2 = 5.0 x 103W