Virginia voters will go to the polls Tuesday to select candidates for statewide contests as well as House of Delegates races. In statewide contests, Democrats will choose candidates for lieutenant governor and attorney general. Here’s what voters need to know about the primaries:

QWho is on the statewide ballot?

AThe lieutenant governor race is between Arlington County’s Aneesh Chopra, the United States’ first chief technology officer under President Obama, and state Sen. Ralph S. Northam of Norfolk.

In the attorney general race, former federal prosecutor Justin E. Fairfax of Fairfax County is running against state Sen. Mark R. Herring of Loudoun County.

Why is there no Democratic candidate for governor on the ballot?

Because businessman Terry McAuliffe was the only Democratic candidate to file for the office of governor, he automatically became the party’s nominee. He faces Attorney General Ken Cuccinelli II (R) in November.

Are there any other primary races?

Yes, three Democratic members of the House of Delegates have primary challengers, and voters in their districts will choose those candidates. (The entire House of Delegates is up for election in November.)

In District 63, Del. Rosalyn R. Dance (Petersburg) faces Evandra D. Thompson.

In District 86, Jennifer B. Boysko and Herbert C. Kemp are vying for the chance to unseat Del. Thomas Davis Rust (R-Fairfax).

In District 90, Del. Algie T. Howell Jr. (Norfolk) is defending his seat against police officer Rick James, who also challenged him in 2011.

There are eight House of Delegates races that will determine the Republican candidates in those districts. Several incumbents have drawn challengers, including Speaker William J. Howell (Stafford), who faces Craig E. Ennis. Other GOP delegates with opponents are C. Todd Gilbert (Shenandoah), Beverly J. Sherwood (Frederick), Joe T. May (Loudoun) and Robert D. “Bobby” Orrock Sr. (Caroline).

How many people are expected to participate in the Democratic primary?

Traditionally, turnout is lower in statewide elections than in years when a presidential candidate is on the ballot. This year, turnout could be even more depressed because there is no gubernatorial candidate running in the primary. Estimates have ranged from 1 percent to 4 percent of the state’s total voting population — between about 54,000 and 214,000 voters.

Virginia voters do not register by party, and anyone can vote in either primary. Polling locations are open from 6 a.m. to 7 p.m.