CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
A 6 Ω resistor is connected across 6 V. Current is:
A. 1 A
B. 0 A
C. 2 A
D. 3 A
Correct Answer: A
I = V/R.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
A 4 Ω resistor is connected across 6 V. Current is:
A. 1.5 A
B. 1.65 A
C. 1.35 A
D. 2.5 A
Correct Answer: A
I = V/R.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
A 3 Ω resistor is connected across 6 V. Current is:
A. 4 A
B. 2 A
C. 3 A
D. 1 A
Correct Answer: B
I = V/R.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
A 2 Ω resistor is connected across 6 V. Current is:
A. 3 A
B. 2 A
C. 5 A
D. 4 A
Correct Answer: A
I = V/R.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
A diode is designed primarily to:
A. measure temperature
B. allow current preferentially in one direction
C. store magnetic energy
D. amplify sound mechanically
Correct Answer: B
A diode rectifies current.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
The SI unit of magnetic flux density is the:
A. weber
B. henry
C. tesla
D. gauss only
Correct Answer: C
Magnetic flux density is in teslas.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
The SI unit of capacitance is the:
A. tesla
B. henry
C. farad
D. weber
Correct Answer: C
Capacitance is in farads.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
A step-up transformer ideally increases:
A. Frequency
B. Total energy
C. Power beyond input
D. Voltage
Correct Answer: D
A step-up transformer increases voltage.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
A transformer operates using:
A. static electricity only
B. direct-current electrolysis
C. electromagnetic induction with alternating current
D. radioactive decay
Correct Answer: C
Transformers need changing magnetic flux.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
Electromagnetic induction occurs when:
A. temperature is fixed
B. magnetic flux through a circuit changes
C. current is always zero
D. resistance is infinite
Correct Answer: B
Changing flux induces emf.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
An electromagnet generally becomes stronger when:
A. the core is always removed
B. coil current is increased
C. coil current is reduced
D. turns are reduced
Correct Answer: B
More current produces a stronger field.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
A fuse protects a circuit mainly by:
A. increasing voltage
B. producing magnetism only
C. storing charge
D. melting when current becomes excessive
Correct Answer: D
A fuse opens the circuit on overcurrent.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
Electrical power is:
A. P = VI
B. P = QV/t²
C. P = I/R
D. P = V/I
Correct Answer: A
P = VI.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
In a parallel circuit, the same quantity across each branch is:
A. Resistance
B. Current
C. Voltage
D. Charge stored
Correct Answer: C
Parallel branches have the same voltage.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
In a series circuit, the same quantity through each component is:
A. Resistance
B. Current
C. Voltage
D. Power
Correct Answer: B
Current is the same in a series path.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
Conventional current in an external circuit is taken to flow from:
A. ground to sky
B. north pole to south pole
C. lower to higher potential only
D. higher potential to lower potential
Correct Answer: D
Conventional current direction is defined from positive to negative potential.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
Electric current is rate of flow of:
A. magnetic flux
B. energy only
C. mass
D. electric charge
Correct Answer: D
I = Q/t.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
Ohm's law is:
A. Q = It
B. P = VI
C. V = IR
D. F = qE
Correct Answer: C
V = IR.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
The SI unit of resistance is the:
A. ohm
B. ampere
C. volt
D. farad
Correct Answer: A
Resistance is measured in ohms.
CSS - PMS - CCE - PCS - Everyday Science
Electricity and Magnetism
The SI unit of potential difference is the:
A. ohm
B. watt
C. ampere
D. volt
Correct Answer: D
Voltage is measured in volts.