Question Library — KalmiPrep by Kalmitech

Physics UTME / JAMB 1980 Electricity and Magnetism

A cell has an open circuit voltage V1 and a closed circuit voltage V2 when a current is flowing through it. Therefore, the internal resistance of the cell is

A

\(\frac{V_2}{I}\)

B

\(\frac{V_1}{I}\)

C

\(\frac{(V_1 + V_2)}{I}\)

D

\(\frac{(V_1 - V_2)}{I}\)

E

\(\frac{(V_2 - V_1)}{I}\)

medium Difficulty

Physics UTME / JAMB 1980 Electricity and Magnetism

According to Ohm's law, the ratio V/I is constant for

A

an electrolyte

B

a diode

C

a transistor

D

silver

E

all of the above

medium Difficulty

Physics UTME / JAMB 1980 Electricity and Magnetism

In the process of electrification by induction, the amount of induced charge in relation to the inducing charge is the

A

same in sign and quantity

B

same in sign but greater

C

opposite in sign but greater

D

opposite in sign but less

E

opposite in sign but equal

medium Difficulty

Physics UTME / JAMB 1979 Electricity and Magnetism

In an electrolysis experiment, a cathode of mass 5g is found o weigh 5.01g after a current of 5A flows for 50 seconds. What is the electrochemical equivalent of the deposited substance?

A

0.00004g/C

B

0.00002g/C

C

0.02500g/C

D

0.05000g/C

E

0.00001g/C

medium Difficulty

Physics UTME / JAMB 1979 Electricity and Magnetism

Which of the following statements about radioactivity are true? i. alpha particle is positively charged ii. Beta particle is negatively charged iii. Gamma ray is neutral iv. Beta particle has the same mass as helium atom v. Gamma ray is charged

A

i, ii, iii and iv only

B

iv and v only

C

i, ii and iii only

D

i, ii and v only

E

all

medium Difficulty

Physics UTME / JAMB 1979 Electricity and Magnetism

A capacitor and a resistor are connected in series with each other and in series with an accumulator of negligible internal resistance. The potential across the terminals of the capacitor is

A

twice the e.m.f of the accumulator

B

less than the e.m.f by the potential drop across the resistor

C

zero

D

the same as the e.m.f.

E

greater than the e.m.f

medium Difficulty

Physics UTME / JAMB 1979 Electricity and Magnetism

In a given circuit, the cell P has an emf 1.5V and an unknown internal resistance while cell Q has an emf 2.0V and an internal resistance of 1 ohm if the ammeter reads 50m A, Then r is equal to

Attached Figure / Diagram

A

0.5 ohm

B

0.62 ohm

C

1.0 ohm

D

2.0 ohm

E

3.0 ohm

medium Difficulty

Physics UTME / JAMB 1979 Electricity and Magnetism

Fig 8 shows a current I flowing in a copper wire situated in a magnetic field existing between the pole-pieces of a horse-shoe magnet. Which of the following statements is correct?

Attached Figure / Diagram

A

The wire will experience a force in the direction into the paper

B

The wire will experience a force in the direction out of the paper

C

The wire will vibrate in a direction into and out of the paper

D

the wire will move in the direction of the field i.e toward the s-pole

E

the wire will not move because it is made of copper which is non magnetic

medium Difficulty

Physics UTME / JAMB 1979 Electricity and Magnetism

An electrical circuit is connected up as shown above, which of the following is correct about the value of current flowing through the 1 ohm resistance?

Attached Figure / Diagram

A

12/13A

B

13/12A

C

1/3A

D

3A

E

12/7A

medium Difficulty

Physics UTME / JAMB 1978 Electricity and Magnetism

Two resistors R1 and R2 are connected in parallel, R2 being greater than R1. The combined resistance is

A

less than R1

B

greater than R2

C

the sum of R1 and R2

D

the difference of R2 and R1

E

greater thanR1 but less than R2

medium Difficulty

Physics UTME / JAMB 1978 Electricity and Magnetism

Three 5 ohms resistors connected in parallel have a potential difference of 60v. applied across the combination. The current in each resistor is

A

4A

B

36A

C

12A

D

24A

E

10A

medium Difficulty

Physics UTME / JAMB 1978 Electricity and Magnetism

In order to convert a galvanometer into an ammeter

A

a low resistance shunt is connected in parallel

B

a low resistance shunt is connected in series

C

a medium resistance shunt is connected in series

D

a high resistance shunt is connected in parallel

E

a high resistance shunt is connected in series

medium Difficulty

Physics UTME / JAMB 1978 Electricity and Magnetism

In a D.C. circuit, a 10 microfarad (mf) capacitor is placed in series with a 10 0hm resistor. The total resistance of the combination is

A

10 ohms

B

1 ohms

C

zero

D

20 ohms

E

infinite

medium Difficulty

Physics UTME / JAMB 1978 Electricity and Magnetism

The electric supply from Kainji Dam is transmitted at high voltages of the order hundreds of kilovolts but is converted to domestic use of about 220 volts by

A

commutators

B

transistors

C

valves and diodes

D

rectifiers

E

transformers

medium Difficulty

Physics UTME / JAMB 1978 Electricity and Magnetism

Every house supplied with electricity is provided with a box of fuses so that

A

the consumption of electricity can be recorded

B

people residing in the house will not have an electric shock if they touch a live wire

C

the total current drawn from the mains can be limited

D

the voltage supply can be stabilized

E

it serves as a standby supply when there is a power failure

medium Difficulty