Paper 1 DC Circuits Drills

Q1

In a series circuit, current through each resistor is

A. the same.
B. split equally always.
C. zero.
D. proportional to resistance squared.

Q2

In a parallel circuit, p.d. across each branch is

A. the same.
B. split in proportion to resistance.
C. zero.
D. unrelated to source p.d.

Q3

Two resistors $3\Omega$ and $6\Omega$ in series have effective resistance

A. $2\Omega$
B. $3\Omega$
C. $9\Omega$
D. $18\Omega$

Q4

Two resistors $3\Omega$ and $6\Omega$ in parallel have effective resistance

A. $2\Omega$
B. $3\Omega$
C. $9\Omega$
D. $18\Omega$

Q5

An ideal ammeter should be connected

A. in series and have very low resistance.
B. in parallel and have very high resistance.
C. in series and have very high resistance.
D. across the cell only.

Q6

An ideal voltmeter should be connected

A. in series and have low resistance.
B. in parallel and have high resistance.
C. in parallel and have zero resistance.
D. replacing the source.

Q7

In a potential divider with $R_1$ above $R_2$, output across $R_2$ is

A. $V_{out}=V_s{R}_2/(R_1+R_2)$.
B. $V_s{R}_1/(R_1+R_2)$.
C. $V_s(R_1+R_2)/R_2$.
D. zero always.

Q8

If the lower resistor in a potential divider increases, output p.d. across it

A. increases.
B. decreases.
C. is zero.
D. is independent of resistance.

Q9

A potentiometer balance point is a

A. maximum-current condition.
B. null-current condition through the detector.
C. short circuit.
D. heating condition.

Q10

At potentiometer balance, the unknown p.d. equals

A. potential drop along the balancing length.
B. total supply p.d. always.
C. detector resistance.
D. zero always.

Q11

Short-circuiting a component means it is bypassed by

A. a high-resistance path.
B. a low-resistance path.
C. an open switch.
D. a voltmeter only.

Q12

An open circuit usually makes current in that branch

A. zero.
B. infinite.
C. double.
D. negative always.

Q13

Lamp brightness is most directly related to

A. power dissipated.
B. resistance label only.
C. wire colour.
D. circuit diagram size.

Q14

Adding a resistor in series to a circuit generally makes total resistance

A. increase.
B. decrease.
C. zero.
D. unchanged.

Q15

Adding a resistor in parallel generally makes effective resistance

A. increase.
B. decrease.
C. infinite.
D. unchanged.

Q16

At a junction, total current entering equals

A. total current leaving.
B. total p.d. leaving.
C. total resistance.
D. emf only.

Q17

Around a complete loop in a circuit, energy per unit charge is conserved by balancing

A. emf rises and p.d. drops.
B. masses.
C. wavelengths.
D. densities.

Q18

A thermistor in a divider has resistance that usually decreases when

A. temperature increases.
B. light intensity increases.
C. pressure decreases only.
D. current is zero always.

Q19

An LDR resistance usually decreases when

A. light intensity increases.
B. temperature decreases.
C. voltage is zero only.
D. mass increases.

Q20

A voltmeter connected in series can seriously affect a circuit because it has

A. very high resistance.
B. zero resistance.
C. no terminals.
D. no scale.