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10 سوالات: ایم ڈی کیٹ طبیعیات، جوابات اور وضاحت کے ساتھ۔
A 12 V battery is connected across a 4 ohm resistor. What current flows?
Resistors of 2, 3 and 5 ohms are connected in series. What is the total resistance?
A 6 ohm and a 3 ohm resistor are connected in parallel. What is the equivalent resistance?
An appliance on 220 V draws 2 A. What is its power?
The SI unit of capacitance is the:
درست جواب: Farad
Capacitance is measured in farads. The henry is for inductance, the tesla for magnetic field and the weber for magnetic flux.
The magnetic force on a moving charge is always:
درست جواب: Perpendicular to its velocity
F = qvB sin θ acts at right angles to the velocity, so the force changes the direction of motion but not the speed.
A step-up transformer has:
درست جواب: More turns in the secondary coil
The output voltage is larger when the secondary has more turns than the primary.
Faraday's law of induction states that the induced emf is proportional to:
درست جواب: The rate of change of magnetic flux
The induced emf depends on how fast the flux linked with the circuit changes.
How much electrical energy does a 2 kW heater use in 3 hours?
Lenz's law is a consequence of the conservation of:
درست جواب: Energy
The induced current opposes the change that causes it. If it did not, energy would appear from nothing.